CN113076600B - Helicopter floating stability verification method - Google Patents
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Abstract
The invention belongs to the technical field of design and verification of the water floating characteristic of a helicopter, and particularly relates to a helicopter floating stability verification method. The method comprises the following steps: the method comprises the following steps: carrying out a regular wave test of the scaling helicopter model to obtain test data; step two: carrying out irregular wave test on the scaled helicopter model to obtain test data; step three: establishing a floating response calculation model of a scaled helicopter model of the helicopter, calculating the regular wave floating characteristic of the scaled helicopter model, and iteratively correcting the calculation method according to the result of the regular wave test data in the step S1; step four: on the basis of the corrected regular wave calculation method obtained in the third step, calculating the irregular wave floating characteristic of the scaling helicopter model and verifying, if the verification fails, returning to the third step, and iterating and correcting again; step five: and predicting the floating response of the higher sea state condition by using the calculation method verified by the step four.
Description
Technical Field
The invention belongs to the technical field of design and verification of the water floating characteristic of a helicopter, and particularly relates to a helicopter floating stability verification method.
Background
Helicopter floating stability is one of the important design requirements of ship-based helicopters and helicopters applying for water operation. The helicopter with stable floating time can greatly improve the escape probability of passengers when the helicopter is forced to fall on the water surface. Therefore, the helicopter floating stability test is a very important link in the design process of the overwater floating capacity of the helicopter and is also necessary work for ship-borne helicopter identification and naval evidence obtaining of civil helicopters running on the water surface. In order to fully verify the water surface floating characteristic of the helicopter, improve the safety of the helicopter in water operation and reduce the development cost, a floating stability test based on a scaling helicopter model is needed in the development and verification stages for checking and examining the floating characteristic and investigating whether the helicopter overturns when floating in different sea conditions.
The existing helicopter floating stability test method is to test in a towing tank simulating real sea condition conditions after a scaled helicopter model is adopted. The wave simulation directly adopts irregular waves, namely sea state waves, and long-time floating tests are carried out to verify whether the waves can overturn and the probability of overturning. Because of the limited size of the pool in general, larger scale ratios can be used for larger helicopter sizes to subject the model to higher levels of equivalent sea state.
For the light helicopter, after an overlarge scaling ratio is adopted, the model is too small, and the aspects of gravity center and inertia adjustment, equipment installation and the like are difficult, so that the debugging cost is high, and the debugging period is long. In addition, the irregular waves produced by a general towing tank are lower than the regular waves, but the regular waves cannot be directly used to verify the floating characteristics in the sea state.
The invention aims to provide a new verification method, which solves the problems of pool test and scaling, and enables the existing pool conditions to be suitable for verification of the floating characteristics of helicopters with various sizes and magnitudes.
Disclosure of Invention
The purpose of the invention is as follows: the invention provides a helicopter floating stability verification method, which aims to solve the problems that a pool test condition cannot simulate a high sea condition when a helicopter scaling helicopter model is small in scaling proportion, the scaling proportion is large, and the weight center of gravity and inertia of the model are too small and difficult to adjust.
The technical scheme of the invention is as follows: in order to achieve the above object, a helicopter floating stability verification method is provided, which comprises the following steps:
the method comprises the following steps: carrying out a regular wave test of the scaling helicopter model to obtain test data;
carrying out a floating characteristic test on a scaled helicopter model under different regular wave conditions, acquiring and recording parameters of a roll angle, a pitch angle, a roll angle speed, a pitch angle speed, a yaw angle and a change condition of the model by utilizing test equipment installed in the model, realizing the analysis of one-to-one correspondence between helicopter floating response and regular wave parameters, and acquiring basic data for floating stability calculation under the condition of supporting a large sea condition;
step two: carrying out irregular wave test on the scaled helicopter model to obtain test data;
carrying out a floating characteristic test on a scaled helicopter model under an irregular wave condition, acquiring and recording parameters of a roll angle, a pitch angle, a roll angular velocity, a pitch angular velocity, a yaw angle and a change condition of the model by utilizing test equipment installed in the model, acquiring floating response data of the helicopter under a simulated sea condition, simultaneously recording wave height and period parameters of the simulated sea condition changing along with time, analyzing the response characteristic of the helicopter under the sea condition, and acquiring test data for correcting a calculation method;
step three: establishing a floating response calculation model of a scaled helicopter model of the helicopter, calculating the regular wave floating characteristic of the scaled helicopter model, and iteratively correcting the calculation method according to the result of the regular wave test data in the step S1;
calculating helicopter floating response under the condition of regular wave which is the same as the test condition, and iteratively correcting the calculation method until the error between the calculation result and the test result is not more than 10%, thereby laying a foundation for correcting the irregular wave response calculation method in the next step;
in one possible embodiment, to better account for non-linear effects, in developing regular wave simulations, second order stokes waves are used for the calculations,
the equations of motion for a helicopter floating on water are generally described as follows:
wherein [ M ]]Is a generalized quality matrix; [ mu ] of]To add a quality matrix, [ lambda ]]Is damping coefficient, [ K]As a still water recovery matrix, F fk 、F d Respectively Froude Klebsiella force, diffraction force, { x }, respectively,
Respectively a generalized displacement matrix, a generalized velocity matrix and a generalized acceleration matrix;
in the iterative correction process of the calculation method, the quality and the initial condition of the model grid are checked, and the quality and the damping matrix of the model grid are debugged to make the calculation result consistent with the test result;
step four: on the basis of the corrected regular wave calculation method obtained in the third step, calculating the irregular wave floating characteristic of the scaling helicopter model and verifying, if the verification fails, returning to the third step, and iterating and correcting again;
on the basis of the corrected regular wave calculation method obtained in the third step, further calculating the irregular wave response of the scaled helicopter model, and obtaining a calculation result under the same wave condition as that in the second step; comparing the calculation result with the test result under the same condition, if the error between the calculation result and the test result is more than 10%, returning to the third step, and iterating and correcting again until the error is not more than 10%;
for an actual sea surface, the motion of the sea surface is extremely irregular, and the wave height, wavelength and period of each wave are all randomly changed, so that the wave height, wavelength and period of each wave cannot be expressed by using a fixed expression of a regular wave, and when the problem is researched, if the irregular wave is formed by overlapping unit waves with different wave amplitudes, different wavelengths and random phases, a mathematical expression of the wave surface elevation of the irregular wave can be written as follows:
wherein ξ An Is amplitude, k n Is the wave number, x 0 Position in the x-axis direction, ω n Is the wave circular frequency, epsilon n Is a random phase;
through the four steps, the calculation method capable of meeting the verification precision of the floating characteristic of the helicopter scaling helicopter model is obtained.
Step five: predicting the floating response of the higher sea state condition by using the calculation method verified by the fourth step:
by utilizing the calculation method, the floating characteristic of the scaled helicopter model of the helicopter under the condition of higher sea condition is calculated, and the obtained result is converted through a similarity relation and is used for verifying whether the helicopter meets the requirement of upright floating without overturning under the specified sea condition.
The invention has the beneficial effects that: the method ensures the calculation precision of the calculation program, and performs calculation, prediction and verification on the floating stability of the helicopter on the basis of the calculation precision, thereby not only ensuring the credible result, but also avoiding the problems of insufficient water tank capacity and difficult model processing caused by the prior verification only through a test mode, and accelerating the verification of the emergency floating capacity of the helicopter.
Drawings
FIG. 1 is a flow chart of a helicopter floating stability verification method of the invention
FIG. 2 is a schematic view of the helicopter test element installation of the present invention
FIG. 3 is a time history plot of the results of the regular wave test of the present invention
FIG. 4 is a schematic view of the wave height gauge measuring pool simulation sea state parameter of the present invention
FIG. 5 is a comparison graph of the irregular wave test target spectrum and the actual spectrum of the present invention
FIG. 6 is a diagram of the debugging effect of the regular wave calculation program of the present invention
FIG. 7 is a diagram of the debugging effect of the calculation program for different irregular wave test states according to the present invention
Wherein:
1-inertial measurement unit, 2-battery, 3# and 4# fuselage bulkhead, 5-wave height instrument, 6-probe
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, 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 invention.
Fig. 1 shows a flowchart of a helicopter floating stability verification method according to the present invention. The helicopter floating stability verification method comprises the steps of testing, correcting a calculation program and calculating and forecasting. The test content comprises a regular wave test and an irregular wave test, and test data for correcting the calculation program are accumulated through the tests; correcting calculation by using test data, wherein the calculation results of regular waves and irregular waves need to be corrected; after the calculation method is determined by correction, the floating stability forecast of higher sea state is performed by using the determined calculation method.
As shown in fig. 2, which is a schematic view of the sensor of the helicopter floating stability test model of the present invention, before the floating test is performed, the sensor needs to be installed on the model, and the installed sensor is an inertia measurement element 1, and is used for collecting and recording the roll angle, pitch angle, roll angle speed, pitch angle speed, and yaw angle data of the model;
according to the specified weight center of gravity and the specified rotational inertia data, adjusting the model counterweight to meet the requirements, and completing the model preparation;
fig. 3 is a schematic diagram of the experimental pool wave parameter acquisition of the present invention. During the test, wave generation is carried out according to specified parameters, and the height (namely the wave height) and the period of the wave surface are measured by using a probe inserted into a water tank by a wave height instrument, so as to obtain specific parameters of the wave for analyzing the test result.
First, a regular wave test of a scaled helicopter model is performed. Placing the scaling helicopter model in a towing tank, generating waves according to the wave height and the period of a preset regular wave (the wave generation is limited by the capacity of the tank), so that the scaling helicopter model encounters the waves, and recording the roll, pitch and yaw response data of the model through an inertia measurement element on the model; after a wave direction test is finished, manually adjusting the relative direction of the model and the waves to enable the waves to flow from the other direction of the model, repeating the steps, and collecting regular wave response data; each direction should encounter more than about 10 waves to reduce errors in data acquisition;
fig. 3 shows a regular wave response data sample collected by the regular wave test of the scaled helicopter model according to the present invention. Analyzing the parameters shown in the diagram, and eliminating field values in the diagram to obtain regular wave test data which can be used for correction calculation, wherein the regular wave test data comprises response peak values, response valley values, response double amplitude values and response oscillation periods.
Fig. 5 is a schematic diagram showing the wave-making capability inspection of the water tank before the irregular wave test. As shown in fig. 4, the wave height meter measures a schematic diagram of a pool simulating sea condition parameters, the pool performs irregular wave generation according to preset parameters, is limited by the capacity of the pool, collects wave height and period parameters by the wave height meter, acquires an actual irregular wave spectrum, and compares the actual irregular wave spectrum with a target wave spectrum; and continuously debugging pool wave-making parameters until the wave spectrum of the irregular waves generated by the pool is matched with the target wave spectrum.
Then, irregular wave test of scaled helicopter model is performed. Placing a scaled helicopter model in a towing tank, wherein the tank generates waves according to preset wave parameters of irregular waves, so that the scaled helicopter model can generate rolling, pitching and yawing responses when encountering the waves, the model can float in the waves for a long time, the time is more than 300 seconds, the model can fully encounter the big waves and the small waves of the irregular waves, and the irregular wave response data can be obtained by utilizing an inertia measurement unit additionally arranged in the model;
carrying out statistics and processing on the irregular wave data to obtain the maximum value and the minimum value of the roll angle and the pitch angle of the scaled helicopter model in the irregular wave;
establishing a floating response calculation model of a helicopter scaling helicopter model, and selecting a floating response calculation method; in order to better consider the nonlinear influence, when regular wave simulation is carried out, second-order stokes waves are adopted for calculation, and the motion equation of the helicopter floating on water is generally described as follows:
wherein [ M ]]Is a generalized quality matrix; [ mu ] of]To add a quality matrix, [ lambda ]]Is damping coefficient, [ K]As a still water recovery matrix, F fk 、F d Respectively Fourdride Krafft force, diffraction force, { x }, respectively,
Respectively a generalized displacement matrix, a generalized velocity matrix and a generalized acceleration matrix;
in the iterative correction process of the calculation method, the quality and the initial condition of the model grid are checked, and the quality and the damping matrix of the model grid are debugged to make the calculation result consistent with the test result;
and performing regular wave response calculation on the calculation model, setting the wave period, wave height and wavelength conditions adopted by calculation to be the same as the conditions of the regular wave of the test, confirming that the generation quality of the regular wave meets the requirements after the regular wave is generated by the calculation program, and then calculating to obtain the response calculation result of the model in the regular wave.
Fig. 6 is a graph showing the comparison between the calculation result and the test result in the regular wave. Reducing errors between a calculation result of the regular wave and a test result by gradually debugging the calculation model and damping, mass and rigidity parameters in a calculation program until engineering precision requirements are met, and determining debugging parameters;
performing irregular wave response calculation on the calculation model by using a model and a calculation program which are debugged by regular wave data, selecting a target spectrum to generate irregular waves, and calculating to obtain the response of the model in the irregular waves;
analyzing the response calculation result of the irregular wave, analyzing the wave height peak value, the valley value, the sense wave height and the average period parameter of the irregular wave, comparing with the target wave parameter, and confirming that the numerical wave making of the irregular wave meets the requirement; on the basis of the condition, the analysis model calculates the response, such as the maximum value, the minimum value and the double amplitude of the roll angle and the pitch angle, and compares the response with the test result;
as shown in fig. 7, in order to compare the results after the irregular wave response test and the irregular wave response calculation, whether the calculated roll angle peak value, the calculated valley value, and the calculated double amplitude value are consistent with the test result is confirmed by comparison, and if so, the calculation program correction is completed; if the response is inconsistent with the response, returning to the regular wave correction step, and correcting the regular wave and the irregular wave response again;
after the calculation program is corrected, the calculation method is used for calculating the floating characteristic of the scaled helicopter model of the helicopter under the condition of higher sea state, and the obtained result is converted by a similarity relation, namely a payment of the Rude similarity criterion, so that whether the helicopter can finish floating without overturning or not under the condition of higher sea state is verified.
The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. The scope of the present invention is not limited thereto, and any changes or substitutions that can be easily made by those skilled in the art within the technical scope of the present invention will be covered by the scope of the present invention. The protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (6)
1. A helicopter floating stability verification method is characterized by comprising the following steps:
the method comprises the following steps: carrying out a regular wave test of the scaling helicopter model to obtain test data;
step two: carrying out irregular wave test on the scaled helicopter model to obtain test data;
step three: establishing a floating response calculation model of a scaled helicopter model of the helicopter, calculating the regular wave floating characteristic of the scaled helicopter model, and iteratively correcting the calculation method according to the regular wave test data result in the first step; calculating helicopter floating response under the condition of regular wave which is the same as the test condition, and iteratively correcting the calculation method until the error between the calculation result and the test result is not more than 10%, thereby laying a foundation for correcting the irregular wave response calculation method in the next step; when regular wave simulation is carried out, second-order Stokes waves are adopted for calculation,
the equation of motion for a helicopter floating on water is described as follows:
wherein [ M ]]Is a generalized quality matrix; [ mu ] of]To add a quality matrix, [ lambda ]]Is damping coefficient, [ K]As a still water recovery matrix, F fk 、F d Respectively Fourdride Krafft force, diffraction force, { x }, respectively,
Respectively a generalized displacement matrix, a generalized velocity matrix and a generalized acceleration matrix;
in the iterative correction process of the calculation method, the quality and the initial condition of the model grid are checked, and the quality and the damping matrix of the model grid are debugged to make the calculation result consistent with the test result; step four: on the basis of the corrected regular wave calculation method obtained in the third step, calculating the irregular wave floating characteristic of the scaling helicopter model and verifying, if the verification fails, returning to the third step and carrying out iteration correction again; on the basis of the corrected regular wave calculation method obtained in the third step, further calculating the irregular wave response of the scaled helicopter model, and obtaining a calculation result under the same wave condition as that in the second step; comparing the calculation result with the test result under the same condition, if the error between the calculation result and the test result is more than 10%, returning to the third step, and iterating and correcting again until the error is not more than 10%;
assuming that the irregular wave is formed by overlapping unit waves with different amplitudes, different wavelengths and random phases, a mathematical expression of the rise of the wave surface of the irregular wave can be written as follows:
wherein xi is An Is amplitude, k n Is the wave number, x 0 Position in the x-axis direction, ω n Is the wave circular frequency, epsilon n Is a random phase;
through the four steps, a calculation method capable of meeting the verification precision of the helicopter scaling model floating characteristic is obtained;
step five: and predicting the floating response of the higher sea state condition by using the calculation method verified by the step four.
2. A helicopter floating stability verification method according to claim 1, wherein in said step one, a helicopter scaled helicopter model is used to perform floating characteristic tests under different regular wave conditions, the inertial measurement unit installed in the model is used to collect and record the roll angle, pitch angle, roll angular velocity, pitch angular velocity and yaw angular parameter of the model, and the corresponding relation between the helicopter floating response and the regular wave parameters is analyzed to obtain the basic data for supporting the floating stability calculation under the condition of the sea.
3. A helicopter floating stability verification method according to claim 2, wherein in said step two, a scaled helicopter model is used to perform a floating characteristic test under irregular wave conditions, and test equipment installed in the model is used to collect and record the roll angle, pitch angle, roll angular velocity, pitch angular velocity, yaw angular parameter and variation of the model, so as to obtain floating response data of the helicopter under simulated sea condition, and record the wave height and period parameters of the simulated sea condition changing with time, so as to analyze the response characteristic of the helicopter in sea condition, and obtain test data for correcting the calculation method.
4. The helicopter floating stability verification method according to claim 3, characterized in that the wave height meter installed on the pool records the specific wave parameters of the simulated sea state changing with time, analyzes the response characteristics of the helicopter in the sea state, and acquires data for further correcting the floating stability calculation result under the sea state condition.
5. The helicopter floating stability verification method according to claim 4, characterized in that in said fifth step, a calculation method capable of meeting helicopter scaling helicopter model floating characteristic verification accuracy is obtained through the above four steps, and the helicopter scaling helicopter model floating characteristic under a higher simulated sea condition is calculated by using the calculation method.
6. The helicopter floating stability verification method according to claim 5, characterized in that the real helicopter floating stability result is obtained by converting the scaled helicopter model floating stability result obtained by calculation through a similarity relation, and is used for verifying whether the real helicopter meets the requirement of upright floating without overturning under the specified sea condition.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106404344A (en) * | 2016-11-07 | 2017-02-15 | 中国特种飞行器研究所 | Helicopter wind wave rolling model pool test device |
| CN110717216A (en) * | 2019-08-30 | 2020-01-21 | 南京航空航天大学 | Method for forecasting rolling response of helicopter with flexible air bag under irregular wave |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20120152007A1 (en) * | 2007-01-12 | 2012-06-21 | Richard Holmes | Testing performance of a material for use in a jet engine |
| WO2019232667A1 (en) * | 2018-06-04 | 2019-12-12 | 大连理工大学 | Sensor arrangement method for reducing uncertainty in structural mode identification |
-
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- 2021-04-20 CN CN202110423940.1A patent/CN113076600B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106404344A (en) * | 2016-11-07 | 2017-02-15 | 中国特种飞行器研究所 | Helicopter wind wave rolling model pool test device |
| CN110717216A (en) * | 2019-08-30 | 2020-01-21 | 南京航空航天大学 | Method for forecasting rolling response of helicopter with flexible air bag under irregular wave |
Non-Patent Citations (5)
| Title |
|---|
| Actuator Fault Estimation and Reconfiguration Control for the Quad-Rotor Helicopter;Fuyang Chen 等;《International Journal of Advanced Robotic Systems》;20170515;第1-12页 * |
| 一种直升机漂浮稳定性计算方法的研究;陈彬 等;《直升机技术》;20170615(第2期);第6-9,15页 * |
| 波浪对直升机应急漂浮系统稳定性的影响;侯斌;《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅱ辑》;20170315(第03期);第C031-1503页 * |
| 直升机漂浮特性试验技术研究;江婷 等;《实验流体力学》;20200815;第34卷(第4期);第30-35页 * |
| 直升机迫降着水缩比模型试验方法的研究;李涛 等;《计算机与数字工程》;20151020;第43卷(第10期);第1790-1793,1890页 * |
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