Engineering design method of dynamic vibration absorber for local vibration control of helicopter

Abstract

The invention belongs to the field of helicopter vibration control, and relates to a dynamic vibration absorber engineering design method for helicopter local vibration control. The method comprises the steps that the optimal installation position of the dynamic vibration absorber is determined by carrying out dynamic coupling analysis on the dynamic vibration absorber and the helicopter, the optimal effective mass of the dynamic vibration absorber is determined by combining the overall design requirements of the dynamic vibration absorber, and the structural design of the dynamic vibration absorber is carried out on the basis of the effective mass of the dynamic vibration absorber.

Description

Technical Field

[0001] The invention belongs to the field of helicopter vibration control and relates to an engineering design method of a dynamic vibration absorber for local vibration control of a helicopter. Background Art

[0002] Dynamic vibration absorbers are an effective means for local vibration control of helicopters. The vibration control effect of dynamic vibration absorbers depends critically on the installation position of the dynamic vibration absorbers on the helicopter and the dynamic characteristics of the dynamic vibration absorbers after they are installed on the helicopter. Domestic and foreign research on the design of dynamic vibration absorbers mainly focuses on the theoretical research on the dynamic parameters of dynamic vibration absorbers. This patent uses the dynamic vibration absorber and helicopter dynamics coupling analysis method, through the optimization of the installation position of the dynamic vibration absorber and the optimization analysis of the effective mass of the dynamic vibration absorber, which can be applied to the actual engineering design method in a blank area. Summary of the invention

[0003] Purpose of the invention: In order to enable the installed dynamic vibration absorber to play a good vibration control effect, a dynamic vibration absorber engineering design method for local vibration control of helicopters is proposed, which is of great significance for the engineering design of dynamic vibration absorbers for local vibration control of helicopters.

[0004] Technical solution:

[0005] A method for engineering design of a dynamic vibration absorber for local vibration control of a helicopter is provided, comprising:

[0006] By carrying out coupling analysis between dynamic vibration absorber and helicopter dynamics, the optimal installation position of the dynamic vibration absorber is determined. Combined with the overall design requirements of the dynamic vibration absorber, the optimal effective mass of the dynamic vibration absorber is determined. Based on the effective mass of the dynamic vibration absorber, the structural design of the dynamic vibration absorber is carried out.

[0007] Furthermore, the overall design requirements include: vibration control efficiency at the target location, total weight requirements of the dynamic vibration absorber, overall dimensions of the dynamic vibration absorber, and an installation location that meets installation conditions.

[0008] Furthermore, by conducting a coupling analysis between the dynamic vibration absorber and the helicopter dynamics, the optimal installation position of the dynamic vibration absorber is determined, including:

[0009] Clarify the target position of vibration control and the vibration frequency of the target position;

[0010] Determine the theoretical installed operating frequency of the dynamic vibration absorber through the vibration frequency of the target position;

[0011] Based on the helicopter dynamics model, the initial vibration response of the target position is obtained by frequency domain response calculation method.

[0012] n optional installation positions of the dynamic vibration absorber are arranged on the helicopter structure, where n is a positive integer greater than 1;

[0013] Select 1-m positions from n installation positions and combine them to obtain multiple groups of installation position combinations; m is less than n;

[0014] A dynamic model of a dynamic vibration absorber with the same effective mass is established at different installation position combinations, and a dynamic coupling analysis of multiple dynamic vibration absorbers and helicopters is carried out. The vibration response of the target position at different installation position combinations is obtained by using the frequency domain response calculation method; wherein the sum of the effective masses of the dynamic vibration absorbers at different installation position combinations is less than or equal to the total weight requirement of the dynamic vibration absorber;

[0015] The vibration control efficiency of the target position under different combinations of dynamic vibration absorber installation positions is calculated based on the initial vibration response of the target position and the vibration response under different combinations of dynamic vibration absorber installation positions;

[0016] According to the vibration control efficiency of the target position under different combinations of dynamic vibration absorber installation positions, the vibration control efficiency requirements of the target position, and the installation positions with installation conditions, the optimal combination of dynamic vibration absorber installation positions that meet the requirements is selected.

[0017] Furthermore, combined with the overall design requirements of the dynamic vibration absorber, the optimal effective mass of the dynamic vibration absorber is determined, including:

[0018] On the basis of the helicopter dynamics model, dynamic models of dynamic vibration absorbers with different effective masses are established on the optimal combination, and the dynamic coupling analysis of the dynamic vibration absorber and the helicopter is carried out. The vibration response of the target position under different effective masses is obtained through the frequency domain response calculation method; the sum of the effective masses of the dynamic vibration absorber dynamics model is less than or equal to the total weight requirement of the dynamic vibration absorber;

[0019] According to the initial vibration response of the target position and the vibration response under different effective masses, the vibration control efficiency of the target position under different effective masses is calculated;

[0020] According to the vibration control efficiency of the target position under different effective masses, the vibration control efficiency requirements of the target position, the total weight requirements of the dynamic vibration absorber, and the overall size requirements of the dynamic vibration absorber, the effective mass of the dynamic vibration absorber that meets the requirements is selected.

[0021] Furthermore, based on the effective mass of the dynamic vibration absorber, the dynamic vibration absorber structure design is carried out, including:

[0022] The structure of the dynamic vibration absorber is designed according to the effective mass of the dynamic vibration absorber that meets the requirements, the total weight requirement of the dynamic vibration absorber, and the overall dimension requirement of the dynamic vibration absorber.

[0023] Furthermore, the method further comprises:

[0024] According to the obtained combination of installation positions of the dynamic vibration absorber that meets the requirements, the dynamic vibration absorber is installed according to the structural design of the dynamic vibration absorber; and the installation working frequency is set;

[0025] Conduct flight tests;

[0026] Verify the vibration control effect of the dynamic vibration absorber by analyzing the test flight data;

[0027] If the vibration control effect of the dynamic vibration absorber does not meet the requirements, the effective mass of the dynamic vibration absorber is adjusted, the installed operating frequency is reset, and the flight test is carried out again until the vibration control effect of the dynamic vibration absorber meets the requirements.

[0028] Furthermore, the operating frequency of the dynamic vibration absorber dynamic model is consistent with the theoretical installed operating frequency.

[0029] Beneficial effects:

[0030] The dynamic vibration absorber designed according to the engineering design method of the present invention has a good vibration control effect, which proves that the engineering design method of the present invention provides an effective engineering practical design means for the local vibration control of helicopters and has a high engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A flow chart of the engineering design method of a dynamic vibration absorber for local vibration control of helicopters;

[0032] Figure 2 is a schematic diagram of the initial vibration response of the target position;

[0033] Figure 3 Schematic diagram of the vibration response of the target position under different combinations of installation positions;

[0034] Figure 4 Schematic diagram of the vibration control efficiency of the target position under different combinations of installation positions;

[0035] Figure 5 Schematic diagram of the vibration response of the target position under different effective masses;

[0036] Figure 6 Schematic diagram of the vibration control efficiency of the target position under different effective masses;

[0037] Figure 7 It is a dynamic vibration absorber used for local vibration control of helicopters;

[0038] Figure 8 It is a schematic diagram of the installation frequency setting of the dynamic vibration absorber;

[0039] Fig. 9 This is a diagram of the vibration control effect of the dynamic vibration absorber (flight test data). DETAILED DESCRIPTION

[0040] This patent adopts the coupling analysis method of dynamic vibration absorber and helicopter dynamics, and through the optimization of the installation position of the dynamic vibration absorber and the optimization analysis of the effective mass of the dynamic vibration absorber, the engineering design method that can be applied to engineering practice is in a blank field. In view of the actual vibration problem encountered by a certain type of aircraft, with the purpose of reducing the local vibration at the floor of the helicopter pilot's seat, an engineering design method for a dynamic vibration absorber for local vibration control of helicopters was invented, and a dynamic vibration absorber was designed using the engineering design method in this patent. The test flight method verified that the dynamic vibration absorber has a good vibration control effect on this type of aircraft, thereby verifying the correctness and feasibility of the engineering design method in this patent.

[0041] The following reasons lead to the fact that the dynamic vibration absorber designed only through theoretical research on the dynamic parameters of the dynamic vibration absorber cannot achieve the optimal vibration control effect after installation.

[0042] 1. The dynamic vibration absorber has a good vibration control effect within a certain range near the installation position, but outside this range, there is no vibration control effect or the vibration control effect is poor, that is, the vibration control range of the dynamic vibration absorber is limited and local;

[0043] 2. The range in which the dynamic vibration absorber has a good vibration control effect is directly related to the dynamic parameters of the dynamic vibration absorber. However, after the dynamic vibration absorber is installed in the main system, the dynamic parameters of the dynamic vibration absorber are coupled with the nearby structural stiffness and mass distribution, which changes the local dynamic characteristics of the dynamic vibration absorber and the main system at the installation location. Therefore, it is necessary to carry out dynamic coupling analysis between the dynamic vibration absorber and the main system when designing the dynamic vibration absorber engineering;

[0044] 3. The vibration control effect of the dynamic vibration absorber on the vibration control target position (hereinafter referred to as the target position) depends on the installation position of the dynamic vibration absorber on the main system, that is, the transfer function from the installation position of the dynamic vibration absorber to the target position. Different installation positions of the dynamic vibration absorber have different transfer functions and thus have different vibration control effects. Therefore, there is an optimal installation position for the dynamic vibration absorber, and it is necessary to carry out optimization of the installation position of the dynamic vibration absorber;

[0045] Based on the above discussion, in order to make the installed dynamic vibration absorber play a good vibration control effect, a dynamic vibration absorber engineering design method for helicopter local vibration control is proposed, which is of great significance for the engineering design of dynamic vibration absorber for helicopter local vibration control.

[0046] The present invention determines the optimal installation position of the dynamic vibration absorber by conducting a coupling analysis between the dynamic vibration absorber and the helicopter dynamics, and determines the optimal effective mass of the dynamic vibration absorber in combination with the overall design requirements of the dynamic vibration absorber (such as the vibration control efficiency at the target position, the total weight of the dynamic vibration absorber, the overall dimensions of the dynamic vibration absorber, and the installation position with installation conditions, etc.), and conducts the structural design of the dynamic vibration absorber based on the effective mass of the dynamic vibration absorber. Figure 1 As shown, the specific steps are as follows:

[0047] [1] Define the target position for vibration control and the vibration frequency at the target position;

[0048] [2] Determine the theoretical installed operating frequency of the dynamic vibration absorber through the vibration frequency of the target position;

[0049] [3] Based on the helicopter dynamics model, the initial vibration response of the target position was obtained by frequency domain response calculation method;

[0050] [4] Based on the helicopter dynamics model, a dynamic vibration absorber dynamics model with the same effective mass at different installation position combinations is established, and the dynamic coupling analysis of the dynamic vibration absorber and the helicopter is carried out. The vibration response of the target position at different dynamic vibration absorber installation position combinations is obtained by using the frequency domain response calculation method.

[0051] [5] The vibration control efficiency of the target position under different combinations of dynamic vibration absorber installation positions is calculated based on the initial vibration response of the target position and the vibration response under different combinations of dynamic vibration absorber installation positions;

[0052] [6] According to the vibration control efficiency of the target position under different combinations of dynamic vibration absorber installation positions, the vibration control efficiency requirements of the target position, and the installation positions with installation conditions, a combination of dynamic vibration absorber installation positions that meets the requirements is selected;

[0053] [7] Based on the helicopter dynamics model, a dynamic vibration absorber dynamics model with different effective masses is established on the same dynamic vibration absorber installation position combination that meets the requirements. The dynamic coupling analysis of the dynamic vibration absorber and the helicopter is carried out, and the vibration response of the target position under different effective masses is obtained through the frequency domain response calculation method.

[0054] [8] Based on the initial vibration response of the target position and the vibration response under different effective masses, the vibration control efficiency of the target position under different effective masses is calculated;

[0055] [9] According to the vibration control efficiency of the target position under different effective masses, the vibration control efficiency requirement of the target position, the total weight requirement of the dynamic vibration absorber, and the overall dimension requirement of the dynamic vibration absorber, the effective mass of the dynamic vibration absorber that meets the requirements is selected;

[0056]

[10] Designing the structure of the dynamic vibration absorber according to the obtained effective mass of the dynamic vibration absorber, the total weight requirement of the dynamic vibration absorber, and the overall dimension requirement of the dynamic vibration absorber;

[0057]

[11] According to the obtained combination of installation positions of the dynamic vibration absorber that meets the requirements, the dynamic vibration absorber is installed and the installation operating frequency is set.

[0058]

[12] The vibration control effect of the dynamic vibration absorber was verified by analyzing the test flight data.

[0059] Application examples:

[0060] In order to prove the applicability and effectiveness of the present invention, a dynamic vibration absorber was designed by applying the present invention to reduce the local vibration of the helicopter pilot's seat floor in response to the actual vibration problem encountered by a certain type of aircraft. The dynamic vibration absorber was verified to have a good vibration control effect through test flights. The specific implementation is as follows:

[0061] [1] Figure 1 As shown, firstly, the floor of a certain type of helicopter pilot seat is clearly defined as the target position for vibration control, and the vibration frequency is NΩ, where: N is the number of blades, and Ω is the rotor speed;

[0062] [2] According to the vibration frequency of the target position, the installed operating frequency of the dynamic vibration absorber is determined to be NΩ;

[0063] [3] Based on a helicopter dynamics model, the initial vibration response of the target position was obtained by frequency domain response calculation method. Figure 2 ;

[0064] [4] Based on the dynamic model of a certain type of helicopter, a dynamic model of a dynamic vibration absorber with an effective mass of 5 kg was established in different installation position combinations (combination 1-combination 6), and the dynamic coupling analysis of the dynamic vibration absorber and a certain type of helicopter was carried out. The vibration response of the target position under different dynamic vibration absorber installation position combinations was obtained by frequency domain response calculation method. Figure 3 ;

[0065] [5] Based on the initial vibration response of the target position and the vibration response under different combinations of dynamic vibration absorber installation positions, the vibration control efficiency of the target position under different combinations of dynamic vibration absorber installation positions is calculated. Figure 4 ;

[0066] [6] According to the vibration control efficiency of the target position under different combinations of dynamic vibration absorber installation positions, the vibration control efficiency requirements of the target position, and the installation positions with installation conditions, a combination of dynamic vibration absorber installation positions that meet the requirements is selected, including combination 3, combination 4, and combination 6;

[0067] [7] Based on the helicopter dynamics model, the dynamic vibration absorber installation position combination 3 was selected, and the dynamic vibration absorber dynamics model with different effective masses (5-20 kg) was established at this combination position. The dynamic coupling analysis of the dynamic vibration absorber and the helicopter was carried out, and the vibration response of the target position under different effective masses was obtained by the frequency domain response calculation method. Figure 5 ;

[0068] [8] Based on the initial vibration response of the target position and the vibration response under different effective masses, the vibration control efficiency of the target position under different effective masses is calculated. Figure 6 ;

[0069] [9] According to the vibration control efficiency of the target position under different effective masses, the vibration control efficiency requirements of the target position, the total weight requirements of the dynamic vibration absorber, and the overall size requirements of the dynamic vibration absorber, the effective mass of the dynamic vibration absorber that meets the requirements is selected, including 6kg, 8kg, and 10kg;

[0070]

[10] Based on the obtained effective mass of the dynamic vibration absorber that meets the requirements, the total weight requirement of the dynamic vibration absorber, and the overall dimension requirement of the dynamic vibration absorber, the dynamic vibration absorber structure design is carried out. Figure 7 ;

[0071]

[11] According to the obtained combination of dynamic vibration absorber installation positions that meet the requirements, the dynamic vibration absorber is installed and the installed operating frequency is set to NΩ, see Figure 8 ;

[0072]

[12] By analyzing the test flight data, it was verified that the dynamic vibration absorber has good vibration control effect and meets the design requirements. Fig. 9 .

Claims

1. A method for engineering design of a dynamic vibration absorber for local vibration control of a helicopter, characterized in that: include: By carrying out coupling analysis between dynamic vibration absorber and helicopter dynamics, the optimal installation position of the dynamic vibration absorber is determined. Combined with the overall design requirements of the dynamic vibration absorber, the optimal effective mass of the dynamic vibration absorber is determined. Based on the effective mass of the dynamic vibration absorber, the structural design of the dynamic vibration absorber is carried out.

2. The method according to claim 1, characterized in that The overall design requirements include: vibration control efficiency at the target location, total weight requirements of the dynamic vibration absorber, overall dimensions of the dynamic vibration absorber, and an installation location that meets installation conditions.

3. The method according to claim 2, characterized in that The optimal installation position of the dynamic vibration absorber is determined by conducting a coupling analysis between the dynamic vibration absorber and the helicopter dynamics, including: Clarify the target position of vibration control and the vibration frequency of the target position; Determine the theoretical installed operating frequency of the dynamic vibration absorber through the vibration frequency of the target position; Based on the helicopter dynamics model, the initial vibration response of the target position is obtained by frequency domain response calculation method. n optional installation positions of the dynamic vibration absorber are arranged on the helicopter structure, where n is a positive integer greater than 1; Select 1-m positions from n installation positions and combine them to obtain multiple groups of installation position combinations; m is less than n; A dynamic model of a dynamic vibration absorber with the same effective mass is established at different installation position combinations, and a dynamic coupling analysis of multiple dynamic vibration absorbers and helicopters is carried out. The vibration response of the target position at different installation position combinations is obtained by using the frequency domain response calculation method; wherein the sum of the effective masses of the dynamic vibration absorbers at different installation position combinations is less than or equal to the total weight requirement of the dynamic vibration absorber; The vibration control efficiency of the target position under different combinations of dynamic vibration absorber installation positions is calculated based on the initial vibration response of the target position and the vibration response under different combinations of dynamic vibration absorber installation positions; According to the vibration control efficiency of the target position under different combinations of dynamic vibration absorber installation positions, the vibration control efficiency requirements of the target position, and the installation positions with installation conditions, the optimal combination of dynamic vibration absorber installation positions that meet the requirements is selected.

4. The method according to claim 3, characterized in that Combined with the overall design requirements of the dynamic vibration absorber, determine the optimal effective mass of the dynamic vibration absorber, including: On the basis of the helicopter dynamics model, dynamic models of dynamic vibration absorbers with different effective masses are established on the optimal combination, and the dynamic coupling analysis of the dynamic vibration absorber and the helicopter is carried out. The vibration response of the target position under different effective masses is obtained through the frequency domain response calculation method; the sum of the effective masses of the dynamic vibration absorber dynamics model is less than or equal to the total weight requirement of the dynamic vibration absorber; According to the initial vibration response of the target position and the vibration response under different effective masses, the vibration control efficiency of the target position under different effective masses is calculated; According to the vibration control efficiency of the target position under different effective masses, the vibration control efficiency requirements of the target position, the total weight requirements of the dynamic vibration absorber, and the overall size requirements of the dynamic vibration absorber, the effective mass of the dynamic vibration absorber that meets the requirements is selected.

5. The method according to claim 4, characterized in that Based on the effective mass of the dynamic vibration absorber, the dynamic vibration absorber structure design is carried out, including: The structure of the dynamic vibration absorber is designed according to the effective mass of the dynamic vibration absorber that meets the requirements, the total weight requirement of the dynamic vibration absorber, and the overall dimension requirement of the dynamic vibration absorber.

6. The method according to claim 5, characterized in that The method further comprises: According to the obtained combination of installation positions of the dynamic vibration absorber that meets the requirements, the dynamic vibration absorber is installed according to the structural design of the dynamic vibration absorber; and the installation working frequency is set; Conduct flight tests; Verify the vibration control effect of the dynamic vibration absorber by analyzing the test flight data; If the vibration control effect of the dynamic vibration absorber does not meet the requirements, adjust the effective mass of the dynamic vibration absorber, reset the installed operating frequency, and conduct the flight test again until the vibration control effect of the dynamic vibration absorber meets the requirements.

7. The method according to claim 2, characterized in that The operating frequency of the dynamic vibration absorber dynamic model is consistent with the theoretical installed operating frequency.

8. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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