CN110717216A - Method for forecasting rolling response of helicopter with flexible air bag under irregular wave - Google Patents
Method for forecasting rolling response of helicopter with flexible air bag under irregular wave Download PDFInfo
- Publication number
- CN110717216A CN110717216A CN201910813301.9A CN201910813301A CN110717216A CN 110717216 A CN110717216 A CN 110717216A CN 201910813301 A CN201910813301 A CN 201910813301A CN 110717216 A CN110717216 A CN 110717216A
- Authority
- CN
- China
- Prior art keywords
- helicopter
- under
- wave
- roll
- finite element
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000004044 response Effects 0.000 title claims abstract description 55
- 238000005096 rolling process Methods 0.000 title claims abstract description 45
- 230000001788 irregular Effects 0.000 title claims abstract description 38
- 238000000034 method Methods 0.000 title claims abstract description 27
- 238000013016 damping Methods 0.000 claims abstract description 36
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 29
- 238000004364 calculation method Methods 0.000 claims abstract description 20
- 238000010168 coupling process Methods 0.000 claims abstract description 14
- 239000007787 solid Substances 0.000 claims abstract description 12
- 230000008878 coupling Effects 0.000 claims abstract description 11
- 238000005859 coupling reaction Methods 0.000 claims abstract description 11
- 230000002706 hydrostatic effect Effects 0.000 claims description 18
- 230000003068 static effect Effects 0.000 claims description 10
- 230000001133 acceleration Effects 0.000 claims description 6
- 230000009471 action Effects 0.000 claims description 5
- 230000005484 gravity Effects 0.000 claims description 5
- 230000000694 effects Effects 0.000 claims description 4
- 238000001228 spectrum Methods 0.000 claims description 3
- 238000013277 forecasting method Methods 0.000 claims 3
- 238000004088 simulation Methods 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 9
- 238000004458 analytical method Methods 0.000 description 5
- 238000004422 calculation algorithm Methods 0.000 description 5
- 238000011160 research Methods 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005312 nonlinear dynamic Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000002435 rhinoplasty Methods 0.000 description 1
- 238000002076 thermal analysis method Methods 0.000 description 1
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
Abstract
The application discloses a method for forecasting rolling response of a helicopter with a flexible airbag under an irregular wave, and belongs to the field of helicopter forced landing overwater floating and overturning. The method comprises the following steps: dividing a finite element grid aiming at a helicopter with a flexible air bag of a certain model; importing the data into finite element calculation software to obtain a helicopter roll stability curve, a helicopter roll response curve under a still water surface and two regular waves; obtaining a damping term in a roll dynamics equation according to a damping formula considering a nonlinear term and a helicopter roll response curve under a still water surface; obtaining wave surface equations under regular waves and irregular waves through Matlab programming; and substituting the wave surface equation and the helicopter roll stability curve under the irregular waves into a roll dynamics equation to obtain a helicopter roll response curve under the irregular waves. According to the method, the rolling response condition of the helicopter under the irregular wave can be forecasted and obtained only through simple programming and a plurality of helicopter fluid-solid coupling simulation calculations under simple water surface conditions.
Description
Technical Field
The application relates to the field of helicopter forced landing overwater floating and overturning, in particular to a method for forecasting rolling response of a helicopter with a flexible airbag under an irregular wave.
Background
At present, the research on the floating of helicopters on water at home and abroad is relatively less, and the numerical simulation calculation is mostly carried out in a mode of equivalently converting helicopters with floating systems into single rigid bodies. In fact, according to different floating systems, the influence caused by the rigidity and flexibility of the air bag and the connecting belt is huge, and calculation shows that for the transverse stability of a certain type of helicopter, when the flexibility of the air bag and the connecting belt is not considered, the maximum error of the stability curve calculation is up to 83.3% compared with the test, and when the flexibility of the air bag is considered, the maximum error of the calculation is only 19.1% compared with the test. Meanwhile, the waves on the actual sea surface are complex, and are usually irregular waves under the same sea condition according to different sea condition definitions.
However, in the research process of the present application, the inventor finds that the existing calculation method considering the multipurpose direct fluid-solid coupling of the flexible airbag and the connecting band has a long calculation time, and the fluid-solid coupling generally cannot give a calculation result in a short time, so that an efficient calculation method needs to be found to research the lateral response condition of the helicopter under irregular waves when the flexibility of the airbag and the connecting band is considered.
Disclosure of Invention
The application provides a method for forecasting rolling response of a helicopter with a flexible airbag under irregular waves, which aims to solve the problem that the existing method for calculating the rolling response of the helicopter with the flexible airbag is too long in calculation time.
A method for forecasting rolling response of a helicopter with a flexible airbag under irregular waves comprises the following steps:
(1) dividing a finite element grid aiming at a helicopter with a flexible air bag of a certain model;
(2) importing the finite element mesh into finite element calculation software to obtain a helicopter roll stability curve, a helicopter roll response curve under a still water surface and two regular waves;
(3) obtaining a damping term in a roll dynamics equation according to a damping formula considering a nonlinear term and a helicopter roll response curve under the hydrostatic surface;
(4) obtaining wave surface equations under regular waves and irregular waves through Matlab programming;
(5) substituting the wave surface equation under the regular waves, the helicopter rolling response curve and the helicopter roll stability curve under the regular waves into the rolling dynamics equation, and verifying the accuracy of the damping term;
(6) and (3) if the damping term is accurate, substituting the wave surface equation and the helicopter transverse stationarity curve under the irregular wave into a roll dynamics equation to obtain a helicopter roll response curve under the irregular wave, and if the damping term is inaccurate, repeating the steps (2) to (5).
Preferably, the step of importing the finite element mesh into finite element calculation software to obtain a helicopter roll stability curve, a helicopter roll response curve under a still water surface and two regular waves includes:
guiding the finite element mesh into finite element calculation software, and obtaining a transverse stationarity curve of the helicopter by an equivalent water area pressure method;
and establishing a corresponding water pool by a fluid-solid coupling method, and performing penalty function coupling on the helicopter integral finite element model and the numerical water pool to obtain helicopter rolling response curves under a still water surface and under two regular waves.
Preferably, the step of introducing the finite element mesh into finite element calculation software and obtaining a helicopter roll stability curve by an equivalent water area pressure method includes:
and importing the finite element grid into finite element calculation software, equating the effect of the whole hydrostatic domain on the helicopter as the effect of static pressure on the helicopter, and executing explicit finite element calculation to finally obtain a transverse stability curve of the helicopter by adding gravity to the helicopter as a whole and adding a static pressure function P (rho gh + cvi) related to the height to each unit, wherein P is the size of the static pressure, rho is the density of water, g is the acceleration of gravity, h is the distance between the center of the unit and the water line surface, c is a damping coefficient, v is the center speed of the unit, and i is the normal direction of the unit.
Preferably, the damping formula considering the non-linear term is:
wherein ,is the resistance borne by the helicopter in motion, mu is the linear term coefficient of the damping force, beta is the nonlinear term coefficient of the damping force,
is the roll angular velocity.
Preferably, the roll dynamics equation is:
wherein ,MB＝W·GM·γ·Θ(t)，IxFor the rolling moment of inertia of helicopters, JxAdds rotational inertia to the roll of the helicopter,is the rolling acceleration of the helicopter,
is a rolling damping item of the helicopter, W is the weight of the whole helicopter,
is a curve of the lateral stationarity of the helicopter,for moment of stationarity of helicopter, MWExternal moment brought by wind, MBFor the external moment brought under the action of waves, GM is the stable center of the helicopter system, gamma is the effective wave inclination coefficient, and theta (t) is the wave surface equation.
Preferably, the first and second electrodes are formed of a metal,
wherein a is the linear coefficient of the helicopter rolling response curve under the hydrostatic surface, and b is the non-linear coefficient of the helicopter rolling response curve under the hydrostatic surfaceThe linear coefficient of the linear coefficient is,
the rolling period is directly obtained by a rolling curve calculated under the hydrostatic surface.
Preferably, the wave surface equation is as follows:
wherein ,
theta (t) is the wave surface equation, i is the variable, aiAmplitude, ω, of the ith sine waveiIs the frequency of the ith sine wave, t is the time, xiiIs the phase angle of the ith sine wave, SW(ωi) Being wave spectra, δ ωiThe frequency step difference of the frequency corresponding to the i frequency is represented by A, e is a natural logarithmic base number, the value is 2.7182, B is a undetermined coefficient B, and H1/3Is the sense wave height, T01Mean wave period, E (ω)i) Is the energy of the corresponding i frequency wave.
Compared with the existing fluid-solid coupling solving and calculating method, the method for forecasting the rolling response of the helicopter with the flexible airbag under the irregular wave band has the following beneficial effects:
the application aims to provide a helicopter with a flexible air bag, and solves the problem that the flexibility description of the air bag and a connecting belt brings low mass computing resources in the fluid-solid coupling solution.
2, different from the regular wave, the calculation of the helicopter rolling response under the regular wave only needs to obtain the periodicity (without rollover) of the helicopter, and usually three to four periodic waves can be finished; however, the irregular waves generate continuous dozens of waves, the period and the wavelength are different, and if the roll response conditions under all the waves are calculated, the fluid-solid coupling can not give out a calculation result in a short time. According to the method for forecasting the rolling response of the helicopter with the flexible airbag under the irregular wave, the rolling response condition of the helicopter under the irregular wave can be forecasted and obtained only through simple programming and helicopter fluid-solid coupling simulation calculation under the condition of a plurality of simple water surfaces.
Drawings
FIG. 1 is a schematic diagram of a finite element mesh of a helicopter with a flexible airbag according to an embodiment of the present application;
fig. 2(a) is a schematic diagram of the helicopter in a state under regular waves at time t-4.08 s;
fig. 2(b) is a schematic diagram of the helicopter in a state under regular waves at time t-4.9 s;
fig. 2(c) is a schematic diagram of the helicopter in a state under regular waves at time t-5.96 s;
fig. 2(d) is a schematic diagram of the helicopter in a state under regular waves at time t-6.51 s;
FIG. 3 is a helicopter roll response curve under a flat hydrostatic surface and under two regular waves;
FIG. 4 is a waveform plot of an irregular wave;
FIG. 5 is a final solved roll response curve for a helicopter with flexible airbags under irregular waves according to an embodiment of the present application;
FIG. 6 is a graph illustrating the roll moment experienced by a helicopter at a plurality of different roll angles in an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments will be described clearly and completely with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
A method for forecasting rolling response of a helicopter with a flexible airbag under irregular waves comprises the following steps:
(1) and (3) dividing a finite element grid aiming at a helicopter with a flexible air bag of a certain model.
Referring to fig. 1, a finite element grid is divided by using Hypermesh software for a certain model of helicopter with flexible airbags.
Hypermesh software is a product of Altair corporation in America, is a world-leading CAE application software package with strong functions, is also an innovative and open enterprise-level CAE platform, integrates various tools required by design and analysis, and has incomparable performance and high openness, flexibility and friendly user interface. For more than 20 years recently, Hypermesh has gradually evolved into the leading pre-processor in the industry, being the first choice for concept and high fidelity modeling. The software has advanced geometry creation and meshing functions, providing an environment that facilitates rapid model generation. Being able to generate high quality grids quickly is one of the core functions of Hypermesh.
Hypermesh supports a plurality of different solver input and output formats, so that after finite element grids of the model are divided by using Hypermesh, the calculation model can be directly converted into different solver file formats, and the calculation is carried out by using corresponding solvers. Hypermesh has a very good solver interface function, so that Hypermesh can be used as a unified CAE application platform of an enterprise, namely, the Hypermsh is uniformly utilized for grid division, then different solvers are utilized for solving different problems, and thus CAE engineers can also conveniently manage data files, and the analysis efficiency can be greatly improved.
(2) And importing the finite element mesh into finite element calculation software to obtain a helicopter roll stability curve, a helicopter roll response curve under a still water surface and two regular waves.
The finite element calculation software is LS-DYNA software, and LS-DYNA is a famous finite element analysis program in the world and is also a well-known rhinoplasty of an explicit integral calculation program. The method is mainly based on Lagrange algorithm, and has ALE algorithm and Euler algorithm; explicit solving is taken as a main part, and an implicit solving function is provided; the structure analysis is taken as the main part, and the functions of thermal analysis and fluid-structure coupling are realized; the method mainly uses nonlinear dynamic analysis and has a static analysis function; the method is based on a finite element algorithm and combines algorithms such as SPH, EFG, volume control and the like. LS-DYNA is widely applied in the engineering field and is recognized as the best explicit analysis software, and the reliability and the accuracy of simulation calculation are proved by comparing the LS-DYNA with experiment results for countless times.
Guiding the divided finite element grids of the helicopter into finite element calculation software, and performing a water area pressure equivalent method, namely, the action of the whole hydrostatic area on the helicopter is equivalent to the action of static pressure on the helicopter, gravity is added to the helicopter as a whole, a static pressure function P which is related to the height is added to each unit, namely rho gh + cvi, so that the transverse stationarity curve of the helicopter is finally obtained by executing the explicit finite element calculation, wherein P is the static pressure, ρ is the density of water, g is the gravitational acceleration, h is the distance from the center of the unit to the water line surface, c is the damping coefficient, v is the unit center velocity, i is the unit normal direction, therefore, the finite element is utilized to solve the transverse moment suffered by the helicopter under a plurality of groups of different transverse angles, and performing point tracing on the multiple groups of data, and finally obtaining a transverse stationarity curve of the helicopter in a curve fitting mode.
The application provides a multiunit different heeling angle under, the experimental data of the heeling moment that the helicopter received is shown as follows:
referring to fig. 6, a graph of roll angle versus roll moment is shown for the above experimental data.
Referring to fig. 2(a), fig. 2(b), fig. 2(c), fig. 2(d) and fig. 3, a corresponding pool is established by a fluid-solid coupling method, and a helicopter integral finite element model is coupled with a numerical pool by a penalty function to obtain helicopter roll response curves under a still water surface and under two regular waves. Fluid-solid coupling is a commonly used method for calculating the force between a fluid and a solid.
The experimental data provided in the embodiment of the present application take setting of a wave height of 0.8m, a wavelength of 8m, and a period of 2s as an example. Fig. 2(a) is a schematic diagram of a state of the helicopter under a regular wave at a time t of 4.08s, fig. 2(b) is a schematic diagram of a state of the helicopter under a regular wave at a time t of 4.9s, fig. 2(c) is a schematic diagram of a state of the helicopter under a regular wave at a time t of 5.96s, fig. 2(d) is a schematic diagram of a state of the helicopter under a regular wave at a time t of 6.51s, fig. 3 is a helicopter roll response curve under a hydrostatic surface and under two regular waves, wherein an abscissa is time, an ordinate is a roll angle, 0 is a helicopter roll response curve under a hydrostatic surface, and 5 is a helicopter roll response curve under two regular waves.
(3) And obtaining a damping term in a roll dynamics equation according to a damping formula considering a nonlinear term and the helicopter roll response curve under the hydrostatic surface.
The damping formula, which takes into account the non-linear term, is:
wherein ,
is the resistance borne by the helicopter in motion, mu is the linear term coefficient of the damping force, beta is the nonlinear term coefficient of the damping force,
is the roll angular velocity.
The roll dynamics equation is:
wherein ,MB＝W·GM·γ·Θ(t)，IxFor the rolling moment of inertia of helicopters, JxAdds rotational inertia to the roll of the helicopter,
is the rolling acceleration of the helicopter,
is a rolling damping item of the helicopter, W is the weight of the whole helicopter,is a curve of the lateral stationarity of the helicopter,
for moment of stationarity of helicopter, MWExternal moment brought by wind, MBFor the external moment brought under the action of waves, GM is the stable center of the helicopter system, gamma is the effective wave inclination coefficient, and theta (t) is the wave surface equation.
And obtaining a damping force linear term coefficient mu and a damping force nonlinear term coefficient beta by means of a Matl ab software analysis curve according to a damping formula considering a nonlinear term and the helicopter rolling response curve under the hydrostatic surface. In the experimental data provided in the examples of the present application, μ ≈ 82.775s was determined-1、β≈0。
(4) And obtaining wave surface equations under regular waves and irregular waves through Matlab programming.
The formula of the wave surface equation is as follows:
wherein ,
theta (t) is the wave surface equation, i is the variable, aiAmplitude, ω, of the ith sine waveiIs the frequency of the ith sine wave, t is the time, xiiIs the phase angle of the ith sine wave, SW(ωi) Being wave spectra, δ ωiThe frequency step difference of the frequency corresponding to the i frequency is represented by A, e is a natural logarithmic base number, the value is 2.7182, B is a undetermined coefficient B, and H1/3Is the sense wave height, T01Mean wave period, E (ω)i) Is the energy of the corresponding i frequency wave. t is t
In the embodiment provided by the application, under a regular wave, the wave height is 0.8m, the wavelength is 8m, the period is 2s, and the wave surface equation is Θ (t) equal to 0.4cos (3.14 t); under irregular wave, the superposition wave is defined as 10, the sense wave height is 0.64m, the average period is 2s, and the wave surface equation is that theta (t) is 0.06881 sin (2.401 t +0.5713) +0.04491 sin (2.06 t +1.355) +0.06923 sin (2.243 t +2.861) +0.06971 sin (3.127 t +2.731) +0.06814 sin (2.556 t +0.8288) +0.03765 sin (92 t +0.4554) +0.06873 sin (2.905 t +0.4275) +0.06781 (2.72 t +0.4572) + 42 sin (3927 t +0.07282 t + 4642) and 727.727). Fig. 4 is a waveform curve of an irregular wave, in which the abscissa is time and the ordinate is wave height.
(5) And substituting the wave surface equation under the regular waves, the helicopter rolling response curve and the helicopter roll stability curve under the regular waves into the rolling dynamics equation, and verifying the accuracy of the damping term.
In the experiments provided in the examples of the present application, μ ≈ 82.775s-1Beta ≈ 0 into the roll dynamics equation
In (1). For a regular wave, the wave height is 0.8m, the wavelength is 8m, the period is 2s, the wave surface equation is that Θ (t) is 0.4cos (3.14t), and the amplitude and the period of the output roll angle are respectively solved as follows: amplitude of 3.876 °, cycle 1.978s, and error from the result in step (3) aboveIf the difference is less than 5%, the damping term is correct in value.
(6) And if the damping term is accurate, substituting the wave surface equation and the helicopter roll stability curve under the irregular wave into a roll dynamics equation to obtain a helicopter roll response curve under the irregular wave.
If the damping term is inaccurate, repeating steps (2) through (5).
Fig. 5 is a finally solved roll response curve of the helicopter with flexible airbags under irregular wavebands provided in the embodiment of the present application, where the abscissa is time and the ordinate is roll angle.
Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.
It will be understood that the present application is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the application is limited only by the appended claims.
Claims (7)
1. A method for forecasting rolling response of a helicopter with a flexible airbag under irregular waves is characterized by comprising the following steps:
(1) dividing finite element grids for the helicopter with the flexible air bag;
(2) importing the finite element mesh into finite element calculation software to obtain a helicopter roll stability curve, a helicopter roll response curve under a still water surface and two regular waves;
(3) obtaining a damping term in a roll dynamics equation according to a damping formula considering a nonlinear term and a helicopter roll response curve under the hydrostatic surface;
(4) obtaining wave surface equations under regular waves and irregular waves through Matlab programming;
(5) substituting the wave surface equation under the regular waves, the helicopter rolling response curve and the helicopter roll stability curve under the regular waves into the rolling dynamics equation, and verifying the accuracy of the damping term;
(6) and (3) if the damping term is accurate, substituting the wave surface equation and the helicopter transverse stationarity curve under the irregular wave into a roll dynamics equation to obtain a helicopter roll response curve under the irregular wave, and if the damping term is inaccurate, repeating the steps (2) to (5).
2. The method for forecasting rolling response of a helicopter with a flexible airbag under an irregular wave according to claim 1, wherein the step of importing the finite element mesh into finite element computing software to obtain a helicopter roll stability curve, a helicopter roll response curve under a still water surface and two regular waves comprises the following steps:
guiding the finite element mesh into finite element calculation software, and obtaining a transverse stationarity curve of the helicopter by an equivalent water area pressure method;
and establishing a corresponding water pool by a fluid-solid coupling method, and performing penalty function coupling on the helicopter integral finite element model and the numerical water pool to obtain helicopter rolling response curves under a still water surface and under two regular waves.
3. The method for forecasting rolling response of a helicopter with a flexible airbag under an irregular wave band according to claim 2, wherein the step of introducing the finite element mesh into finite element calculation software and obtaining a curve of the stability of the helicopter through an equivalent water area pressure method comprises the following steps:
and importing the finite element grid into finite element calculation software, equating the effect of the whole hydrostatic domain on the helicopter as the effect of static pressure on the helicopter, and executing explicit finite element calculation to finally obtain a transverse stability curve of the helicopter by adding gravity to the helicopter as a whole and adding a static pressure function P (rho gh + cvi) related to the height to each unit, wherein P is the size of the static pressure, rho is the density of water, g is the acceleration of gravity, h is the distance between the center of the unit and the water line surface, c is a damping coefficient, v is the center speed of the unit, and i is the normal direction of the unit.
4. The irregular downband flexible airbag helicopter roll response prediction method of claim 1 wherein the damping formula that accounts for nonlinear terms is:
wherein ,
is the resistance borne by the helicopter in motion, mu is the linear term coefficient of the damping force, beta is the nonlinear term coefficient of the damping force,is the roll angular velocity.
5. The irregular downband flexible airbag helicopter roll response forecasting method of claim 4, wherein the roll dynamics equation is:
wherein ,MB＝W·GM·γ·Θ(t)，IxFor the rolling moment of inertia of helicopters, JxAdds rotational inertia to the roll of the helicopter,
is the rolling acceleration of the helicopter,
is a helicopter roll damping term, W isThe weight of the whole helicopter is reduced,
is a curve of the lateral stationarity of the helicopter,
for moment of stationarity of helicopter, MWExternal moment brought by wind, MBFor the external moment brought under the action of waves, GM is the stable center of the helicopter system, gamma is the effective wave inclination coefficient, and theta (t) is the wave surface equation.
6. The irregular downband flexible airbag helicopter roll response forecasting method of claim 4,
wherein a is the linear coefficient of the helicopter rolling response curve under the hydrostatic surface, b is the nonlinear coefficient of the helicopter rolling response curve under the hydrostatic surface,
the rolling period is directly obtained by a rolling curve calculated under the hydrostatic surface.
7. The irregular wave band flexible airbag helicopter roll response forecasting method according to claim 1, characterized in that the wave surface equation formula is:
wherein ,
theta (t) is the wave surface equation, i is the variable, aiAmplitude, ω, of the ith sine waveiIs the frequency of the ith sine wave, t is the time, xiiIs the phase angle of the ith sine wave, SW(ωi) Being wave spectra, δ ωiThe frequency step difference of the frequency corresponding to the i frequency is represented by A, e is a natural logarithmic base number, the value is 2.7182, B is a undetermined coefficient B, and H1/3Is the sense wave height, T01Mean wave period, E (ω)i) Is the energy of the corresponding i frequency wave.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910813301.9A CN110717216B (en) | 2019-08-30 | 2019-08-30 | Roll response forecasting method for helicopter with flexible air bags under irregular waves |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910813301.9A CN110717216B (en) | 2019-08-30 | 2019-08-30 | Roll response forecasting method for helicopter with flexible air bags under irregular waves |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110717216A true CN110717216A (en) | 2020-01-21 |
| CN110717216B CN110717216B (en) | 2023-05-23 |
Family
ID=69209568
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910813301.9A Active CN110717216B (en) | 2019-08-30 | 2019-08-30 | Roll response forecasting method for helicopter with flexible air bags under irregular waves |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110717216B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112965032A (en) * | 2021-03-03 | 2021-06-15 | 山东省科学院海洋仪器仪表研究所 | Ultra-short baseline underwater sound positioning system for simulation based on digital model and debugging method |
| CN113076600A (en) * | 2021-04-20 | 2021-07-06 | 中国直升机设计研究所 | Helicopter floating stability verification method |
| CN115270646A (en) * | 2022-06-14 | 2022-11-01 | 华南理工大学 | Hydrodynamic semi-analysis method for irregular bottom-shaped heaving wave energy device in front of partial reflection wall |
| CN115795644A (en) * | 2022-10-08 | 2023-03-14 | 南京航空航天大学 | Method for analyzing lateral stability of helicopter with flexible air bag based on equivalent pressure field |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020175669A1 (en) * | 2001-05-25 | 2002-11-28 | Ziegner Bernhard Alphonso | Film-based microwave and millimeter-wave circuits and sensors |
| CN1721269A (en) * | 2004-07-14 | 2006-01-18 | 郑悦 | Permanently floating vessel and its protection and power |
| CN202953142U (en) * | 2012-11-30 | 2013-05-29 | 上海振华重工(集团)股份有限公司 | Steel cylinder transportation equipment |
| CN104816819A (en) * | 2014-01-31 | 2015-08-05 | 空客直升机 | Buoyancy system for aircraft, and aircraft |
| CN107256280A (en) * | 2017-04-26 | 2017-10-17 | 天津大学 | Ship joins the method for soaking transverse cutting head probability under a kind of calculating random sea condition |
| CN108153976A (en) * | 2017-12-25 | 2018-06-12 | 重庆华渝电气集团有限公司 | The emulation mode and host computer of naval vessel rolling motion in a kind of wave |
| CN108549616A (en) * | 2018-02-28 | 2018-09-18 | 哈尔滨工程大学 | The forecasting procedure that ship based on G-N wave models substantially moves in severe sea condition |
| CN108820155A (en) * | 2018-06-08 | 2018-11-16 | 哈尔滨工程大学 | The ship gyro based on Fuzzy Immune Controller, which subtracts, under a kind of low speed of a ship or plane shakes control method |
| CN109204704A (en) * | 2018-08-17 | 2019-01-15 | 上海睿网新能源科技发展有限公司 | A kind of certainly steady single floating body of the anticollision can be used for loading laser radar system buoy |
| CN109325309A (en) * | 2018-10-23 | 2019-02-12 | 哈尔滨工程大学 | The Three-dimensional Numerical Simulation Method of ship large-amplitude roll movement |
| CN109376427A (en) * | 2018-10-23 | 2019-02-22 | 哈尔滨工程大学 | Consider the three-dimensional numerical method of the Added Resistance of Ships of wall constraint |
| CN109472065A (en) * | 2018-10-23 | 2019-03-15 | 哈尔滨工程大学 | Forecast the three-dimensional numerical method of Low Speed Full Ships Added Resistance under severe sea condition |
-
2019
- 2019-08-30 CN CN201910813301.9A patent/CN110717216B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020175669A1 (en) * | 2001-05-25 | 2002-11-28 | Ziegner Bernhard Alphonso | Film-based microwave and millimeter-wave circuits and sensors |
| CN1721269A (en) * | 2004-07-14 | 2006-01-18 | 郑悦 | Permanently floating vessel and its protection and power |
| CN202953142U (en) * | 2012-11-30 | 2013-05-29 | 上海振华重工(集团)股份有限公司 | Steel cylinder transportation equipment |
| CN104816819A (en) * | 2014-01-31 | 2015-08-05 | 空客直升机 | Buoyancy system for aircraft, and aircraft |
| CN107256280A (en) * | 2017-04-26 | 2017-10-17 | 天津大学 | Ship joins the method for soaking transverse cutting head probability under a kind of calculating random sea condition |
| CN108153976A (en) * | 2017-12-25 | 2018-06-12 | 重庆华渝电气集团有限公司 | The emulation mode and host computer of naval vessel rolling motion in a kind of wave |
| CN108549616A (en) * | 2018-02-28 | 2018-09-18 | 哈尔滨工程大学 | The forecasting procedure that ship based on G-N wave models substantially moves in severe sea condition |
| CN108820155A (en) * | 2018-06-08 | 2018-11-16 | 哈尔滨工程大学 | The ship gyro based on Fuzzy Immune Controller, which subtracts, under a kind of low speed of a ship or plane shakes control method |
| CN109204704A (en) * | 2018-08-17 | 2019-01-15 | 上海睿网新能源科技发展有限公司 | A kind of certainly steady single floating body of the anticollision can be used for loading laser radar system buoy |
| CN109325309A (en) * | 2018-10-23 | 2019-02-12 | 哈尔滨工程大学 | The Three-dimensional Numerical Simulation Method of ship large-amplitude roll movement |
| CN109376427A (en) * | 2018-10-23 | 2019-02-22 | 哈尔滨工程大学 | Consider the three-dimensional numerical method of the Added Resistance of Ships of wall constraint |
| CN109472065A (en) * | 2018-10-23 | 2019-03-15 | 哈尔滨工程大学 | Forecast the three-dimensional numerical method of Low Speed Full Ships Added Resistance under severe sea condition |
Non-Patent Citations (2)
| Title |
|---|
| 段国贺等: "直升机横向漂浮稳定性时域分析方法与验证" * |
| 王明振等: "直升机水上漂浮特性试验与计算分析" * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112965032A (en) * | 2021-03-03 | 2021-06-15 | 山东省科学院海洋仪器仪表研究所 | Ultra-short baseline underwater sound positioning system for simulation based on digital model and debugging method |
| CN113076600A (en) * | 2021-04-20 | 2021-07-06 | 中国直升机设计研究所 | Helicopter floating stability verification method |
| CN113076600B (en) * | 2021-04-20 | 2022-11-04 | 中国直升机设计研究所 | Helicopter floating stability verification method |
| CN115270646A (en) * | 2022-06-14 | 2022-11-01 | 华南理工大学 | Hydrodynamic semi-analysis method for irregular bottom-shaped heaving wave energy device in front of partial reflection wall |
| CN115795644A (en) * | 2022-10-08 | 2023-03-14 | 南京航空航天大学 | Method for analyzing lateral stability of helicopter with flexible air bag based on equivalent pressure field |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110717216B (en) | 2023-05-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110717216A (en) | Method for forecasting rolling response of helicopter with flexible air bag under irregular wave | |
| CN113111430B (en) | Elastic aircraft flight dynamics modeling method based on nonlinear aerodynamic order reduction | |
| CN108763683B (en) | New WENO format construction method under trigonometric function framework | |
| CN108052772A (en) | A kind of geometrical non-linearity static aeroelastic analysis method based on structure reduced-order model | |
| Smith et al. | CFD-based analysis of nonlinear aeroelastic behavior of high-aspect ratio wings | |
| KR102021498B1 (en) | Design method of attitude control system for flight vehicle and computer program | |
| CN102436550B (en) | Self-adaptive simulative method of dam break flood on complex border and actual landform | |
| CN106934185A (en) | A kind of multiple dimensioned flow simulating method of the fluid structurecoupling of elastic fluid | |
| CN108363843A (en) | A kind of full machine Calculate Ways of geometrical non-linearity aeroelastic effect based on structure reduced-order model | |
| CN104281730B (en) | A kind of finite element method of the plate and shell structure dynamic response of large rotational deformation | |
| CN109840349B (en) | Fixed-wing aircraft gust response modeling analysis method | |
| CN106446424A (en) | Unsteady aerodynamic model parameter prediction method | |
| CN107943094A (en) | The sliding-mode control and its controller of a kind of quadrotor | |
| CN104573269B (en) | A kind of cable-membrane analysis Wind-resistant design method based on close coupling overall technology | |
| CN115525980A (en) | Optimization method and optimization device for aerodynamic configuration of reentry vehicle | |
| CN104091003B (en) | Finite element modeling method of large-deformation responses of flexible shell structures during basic movement | |
| Yu et al. | Wind-induced response of an L-shaped cable support glass curtain wall | |
| CN108170898A (en) | A kind of jointed rock slope reliability analysis Lower Bound Limit | |
| Mavriplis et al. | Recent advances in high-fidelity multidisciplinary adjoint-based optimization with the NSU3D flow solver framework | |
| CN112665820B (en) | R-type grid self-adaptive moving method and device based on variable difference and relative displacement | |
| CN102566446A (en) | Method for establishing full-envelope mathematical model of unmanned helicopter based on linear model group | |
| CN109033487A (en) | A kind of aircraft overall probability design method based on Monte Carlo simulation | |
| CN104866688A (en) | Structural element dimension correcting method based on acceleration sensibility analysis | |
| Moreno et al. | A modification to the enhanced correction factor technique to correlate with experimental data | |
| Lamberson et al. | Aeroelastic simulations with modal and finite-element structural solvers using CREATE-AV/Kestrel v5 |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |