CN107066761A - A kind of electric airplane propeller noise computational methods - Google Patents
A kind of electric airplane propeller noise computational methods Download PDFInfo
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Abstract
The present invention proposes a kind of electric airplane propeller noise computational methods, and this method is that the 3-D geometric model of propeller is set up according to the structural parameters of electric airplane propeller；Gridding point is carried out to the flow field regions of the 3-D geometric model of propeller using FInite Element, the propeller flow field after gridding point is obtained；Unsteady pressure solution is carried out to the circulating area of the propeller flow field after gridding point using large eddy simulation computation model, blade surface instantaneous pressure distribution is obtained；Simulation of acoustic field is carried out to acoustic mesh model using acoustic BEM, the radiated noise distribution of propeller is obtained, this method considers each influence factor of noise comprehensively, and result of calculation is accurately and reliably；This method can be used for aerodynamic noise frequency-domain analysis etc., can provide theoretical foundation and technological guidance for effectively reduction propeller noise.
Description
Technical field
The invention belongs to propeller noise analysis and control technology field, and in particular to a kind of electric airplane propeller
Noise calculation method.
Background technology
Electric airplane noise is mainly derived from propeller.Propeller noise can not only influence the environment of airport location,
And propeller noise passes to cabin, driver and passenger's riding comfort can be also influenceed；The sound of the excessive induction of propeller noise
Fatigue and structural vibration, have a significant impact to flight safety.Propeller noise is mainly derived from aerodynamic noise, and machine is produced from noise
Propeller noise is studied in reason not only can estimate its noise figure in the propeller concept phase, can be also effectively reduction spiral
Oar noise provides theoretical foundation and technological guidance.
The content of the invention
In view of the shortcomings of the prior art, the present invention proposes a kind of electric airplane propeller noise computational methods.
A kind of electric airplane propeller noise computational methods, comprise the following steps：
Step 1：The 3-D geometric model of propeller is set up according to the structural parameters of electric airplane propeller；
Step 2：Gridding point is carried out to the flow field regions of the 3-D geometric model of propeller using FInite Element, net is obtained
Propeller flow field after formatting point；
Step 3：The boundary condition of the propeller flow field after gridding point is set, using large eddy simulation computation model to grid
The circulating area for changing the propeller flow field after dividing carries out unsteady pressure solution, obtains blade surface instantaneous pressure distribution；
Step 4：Blade surface instantaneous pressure distribution data are mapped to acoustic mesh model, by the acoustic network model
Unsteady pressure grid regard blade surface instantaneous pressure distribution as blade acoustic part as the boundary condition of structure
Boundary condition, simulation of acoustic field is carried out using acoustic BEM to acoustic mesh model, obtains the radiated noise distribution of propeller.
The structural parameters of the electric airplane propeller include：Propeller blade number, airscrew diameter, airscrew pitch,
Pitch ratio, disk ratio, hub diameter ratio and blade offset.
The use FInite Element carries out gridding point to the flow field regions of the 3-D geometric model of propeller, obtains grid
The detailed process for changing the propeller flow field after dividing is as follows：
The rotary area of the 3-D geometric model of propeller is carried out using the FInite Element of unstructured tetrahedral grid
Grid breaks up, and net is carried out to the circulating area of the 3-D geometric model of propeller using the FInite Element of structuring hexahedral mesh
Format point, obtain the propeller flow field after gridding point.
The boundary condition of propeller flow field after the gridding of the setting point includes：
The inlet pressure boundary condition of circulating area is atmospheric pressure；
Propeller profile boundary types are wall；
The Entry Interface of circulating area is set as pressure inlets；
The exit interface of circulating area is set as pressure export；
Rotary area set overall is interface；
Rotary area fluid continuum type set is fluid.
Beneficial effects of the present invention：
The present invention proposes a kind of electric airplane propeller noise computational methods, and this method considers each influence of noise comprehensively
Factor, result of calculation is accurately and reliably；This method can be used for aerodynamic noise frequency-domain analysis etc., can be carried for effectively reduction propeller noise
For theoretical foundation and technological guidance.
Brief description of the drawings
Fig. 1 is the flow chart of electric airplane propeller noise computational methods in the specific embodiment of the invention；
Fig. 2 is the 3-D geometric model of propeller in the specific embodiment of the invention
Fig. 3 is the three-dimensional geometry grid model of propeller in the specific embodiment of the invention；
Wherein, (a) is the rotary area grid model of propeller；
(b) for propeller rotary area grid model partial enlarged drawing；
(c) it is the whole flow field grid model of propeller；
Fig. 4 is distributed for surrounding radiated noise under propeller different rotating speeds in the specific embodiment of the invention；
Wherein, (a) is the noise profile that frequency is 33.333Hz when propeller front rotating speed is 1000r/min；
(b) it is frequency is 66.7Hz when propeller front rotating speed is 2000r/min noise profile；
(c) it is frequency is 33.333Hz when propeller side rotating speed is 1000r/min noise profile；
(d) it is frequency is 66.7Hz when propeller side rotating speed is 2000r/min noise profile.
Embodiment
The specific embodiment of the invention is described in detail below in conjunction with the accompanying drawings.
A kind of electric airplane propeller noise computational methods, as shown in figure 1, comprising the following steps：
Step 1：The 3-D geometric model of propeller is set up according to the structural parameters of electric airplane propeller.
In present embodiment, the structural parameters of electric airplane propeller include：Propeller blade number, airscrew diameter, spiral shell
Airscrew pitch, pitch ratio, disk ratio, hub diameter ratio and blade offset.
Propeller blade number n=2, airscrew diameter D=1.6m, propeller hub radius Rh=0.06m, rated speed N=
1500r/min。
The 3-D geometric model of the propeller obtained in present embodiment is as shown in Figure 2.
Step 2：Gridding point is carried out to the flow field regions of the 3-D geometric model of propeller using FInite Element, net is obtained
Propeller flow field after formatting point.
In present embodiment, gridding is carried out to the flow field regions of the 3-D geometric model of propeller using ICEM softwares
Point, obtain the propeller flow field after gridding point：
The rotary area of the 3-D geometric model of propeller is carried out using the FInite Element of unstructured tetrahedral grid
Grid breaks up, in such as Fig. 3 shown in (a) and (b), using the FInite Element of structuring hexahedral mesh to the three-dimensional geometry of propeller
The circulating area of model carries out gridding point, obtains in the propeller flow field after gridding point, such as Fig. 3 shown in (c).
Step 3：The boundary condition of the propeller flow field after gridding point is set, using large eddy simulation computation model to grid
The circulating area for changing the propeller flow field after dividing carries out unsteady pressure solution, obtains blade surface instantaneous pressure distribution.
In present embodiment, it is non-fixed that the circulating area of the propeller flow field after gridding point is carried out using Fluent softwares
Normal pressure fluctuation is solved, and obtains blade surface instantaneous pressure distribution.
Step 4：Blade surface instantaneous pressure distribution data are mapped to acoustic mesh model, by the acoustic network model
Unsteady pressure grid regard blade surface instantaneous pressure distribution as blade acoustic part as the boundary condition of structure
Boundary condition, simulation of acoustic field is carried out using acoustic BEM to acoustic mesh model, obtains the radiated noise distribution of propeller.
In present embodiment, the boundary condition of the propeller flow field after the gridding point of setting includes：
The inlet pressure boundary condition of circulating area is atmospheric pressure, and atmospheric pressure is exactly normal atmospheric pressure, sea level
Atmospheric pressure under 15 degrees Celsius.
Propeller profile boundary types are wall.
The Entry Interface of circulating area is set as pressure inlets.
The exit interface of circulating area is set as pressure export.
Rotary area set overall is interface.
Rotary area fluid continuum type set is fluid.
Simulation of acoustic field is carried out to acoustic mesh model using LMS Virtual.Lab boundary elements acoustic tools, spiral is obtained
In the radiated noise distribution of oar, present embodiment, propeller blade turns shown in frequency calculation formula such as formula (1)：
The noise point that frequency is 33.333Hz when propeller front rotating speed is 1000r/min is calculated according to frequency calculation formula
Shown in cloth, such as Fig. 4 (a), the noise profile that frequency is 33.333Hz when propeller front rotating speed is 2000r/min, such as Fig. 4 (b)
It is shown, propeller plane site etc. acoustic pressure line radially annular distribution, at plane sound field center, sound pressure level is maximum, radially
Outwards gradually reduce.When rotating speed is 1000r/min, spherical site sound radiation pressure is 93.1dB to the maximum；When rotating speed is 2000r/
During min, spherical site sound radiation pressure is 111dB to the maximum.
The noise profile that frequency is 33.333Hz when propeller side rotating speed is 1000r/min, shown in such as Fig. 4 (c), spiral
The noise profile that frequency is 66.7Hz when oar side rotating speed is 2000r/min, shown in such as Fig. 4 (d), propeller is in plane sound field
Etc. acoustic pressure line in 8 words be distributed, close to cylinder position acoustic pressure it is relatively low, close to propeller import and export position acoustic pressure compared with
It is high.When rotating speed is 1000r/min, spherical site sound radiation pressure is 86.3dB to the maximum；It is spherical when rotating speed is 2000r/min
Site sound radiation pressure is 104dB to the maximum.
Claims (4)
1. a kind of electric airplane propeller noise computational methods, it is characterised in that comprise the following steps：
Step 1：The 3-D geometric model of propeller is set up according to the structural parameters of electric airplane propeller；
Step 2：Gridding point is carried out to the flow field regions of the 3-D geometric model of propeller using FInite Element, gridding is obtained
Propeller flow field after point；
Step 3：The boundary condition of the propeller flow field after gridding point is set, using large eddy simulation computation model to gridding point
The circulating area of propeller flow field afterwards carries out unsteady pressure solution, obtains blade surface instantaneous pressure distribution；
Step 4：Blade surface instantaneous pressure distribution data are mapped to acoustic mesh model, by the non-fixed of the acoustic network model
Normal pressure fluctuation grid regard blade surface instantaneous pressure distribution as the border of blade acoustic part as the boundary condition of structure
Condition, simulation of acoustic field is carried out using acoustic BEM to acoustic mesh model, obtains the radiated noise distribution of propeller.
2. electric airplane propeller noise computational methods according to claim 1, it is characterised in that the electric airplane spiral shell
The structural parameters of rotation oar include：Propeller blade number, airscrew diameter, airscrew pitch, pitch ratio, disk ratio, hub diameter ratio and
Blade offset.
3. electric airplane propeller noise computational methods according to claim 1, it is characterised in that the use finite element
Method carries out gridding point to the flow field regions of the 3-D geometric model of propeller, obtains the tool of the propeller flow field after gridding point
Body process is as follows：
Grid is carried out to the rotary area of the 3-D geometric model of propeller using the FInite Element of unstructured tetrahedral grid
Differentiation, gridding is carried out using the FInite Element of structuring hexahedral mesh to the circulating area of the 3-D geometric model of propeller
Point, obtain the propeller flow field after gridding point.
4. electric airplane propeller noise computational methods according to claim 1, it is characterised in that the grid of the setting
Changing the boundary condition of the propeller flow field after dividing includes：
The inlet pressure boundary condition of circulating area is atmospheric pressure；
Propeller profile boundary types are wall；
The Entry Interface of circulating area is set as pressure inlets；
The exit interface of circulating area is set as pressure export；
Rotary area set overall is interface；
Rotary area fluid continuum type set is fluid.
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Cited By (7)
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| CN109018397A (en) * | 2018-08-13 | 2018-12-18 | 南京航空航天大学 | Rotor vortex ring state automatic early-warning system and method based on aerodynamic noise monitoring |
| CN110750854A (en) * | 2019-09-02 | 2020-02-04 | 中国第一汽车股份有限公司 | Method for improving accuracy of solving wind noise of automobile based on SNGR method |
| CN111591458A (en) * | 2020-05-29 | 2020-08-28 | 中国航空工业集团公司西安飞机设计研究所 | Design method for noise control in propeller aircraft cabin |
| CN112214944A (en) * | 2020-10-27 | 2021-01-12 | 武汉理工大学 | Method for determining load of airplane subjected to wind shear caused by downburst during takeoff and landing |
| CN112257184A (en) * | 2020-10-30 | 2021-01-22 | 中国航空工业集团公司西安飞机设计研究所 | Method for calculating distribution of aerodynamic noise of propeller along surface of machine body |
| CN112270045A (en) * | 2020-10-30 | 2021-01-26 | 中国航空工业集团公司西安飞机设计研究所 | Turboprop aircraft aerodynamic noise calculation method |
| CN113221409A (en) * | 2021-05-07 | 2021-08-06 | 桂林理工大学 | Two-dimensional numerical simulation method and device for acoustic waves with coupled finite elements and boundary elements |
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Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109018397A (en) * | 2018-08-13 | 2018-12-18 | 南京航空航天大学 | Rotor vortex ring state automatic early-warning system and method based on aerodynamic noise monitoring |
| CN110750854A (en) * | 2019-09-02 | 2020-02-04 | 中国第一汽车股份有限公司 | Method for improving accuracy of solving wind noise of automobile based on SNGR method |
| CN110750854B (en) * | 2019-09-02 | 2022-09-02 | 中国第一汽车股份有限公司 | Method for improving accuracy of solving wind noise of automobile based on SNGR method |
| CN111591458A (en) * | 2020-05-29 | 2020-08-28 | 中国航空工业集团公司西安飞机设计研究所 | Design method for noise control in propeller aircraft cabin |
| CN111591458B (en) * | 2020-05-29 | 2023-03-24 | 中国航空工业集团公司西安飞机设计研究所 | Design method for noise control in propeller aircraft cabin |
| CN112214944A (en) * | 2020-10-27 | 2021-01-12 | 武汉理工大学 | Method for determining load of airplane subjected to wind shear caused by downburst during takeoff and landing |
| CN112257184A (en) * | 2020-10-30 | 2021-01-22 | 中国航空工业集团公司西安飞机设计研究所 | Method for calculating distribution of aerodynamic noise of propeller along surface of machine body |
| CN112270045A (en) * | 2020-10-30 | 2021-01-26 | 中国航空工业集团公司西安飞机设计研究所 | Turboprop aircraft aerodynamic noise calculation method |
| CN112270045B (en) * | 2020-10-30 | 2022-08-19 | 中国航空工业集团公司西安飞机设计研究所 | Turboprop aircraft aerodynamic noise calculation method |
| CN112257184B (en) * | 2020-10-30 | 2022-09-06 | 中国航空工业集团公司西安飞机设计研究所 | Method for calculating distribution of aerodynamic noise of propeller along surface of machine body |
| CN113221409A (en) * | 2021-05-07 | 2021-08-06 | 桂林理工大学 | Two-dimensional numerical simulation method and device for acoustic waves with coupled finite elements and boundary elements |
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