Projectile cone motion test and data processing method under static incoming flow
By using static flow-based cone motion experiments and data processing methods, the problems of testing and processing cone motion of projectiles and rockets were solved, the decomposition and accuracy of projectile force analysis were realized, and flight stability and range prediction were improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XIAN MODERN CONTROL TECH RES INST
- Filing Date
- 2025-12-31
- Publication Date
- 2026-05-19
AI Technical Summary
In the existing technology, the experimental and data processing methods for the conical motion of projectiles and rockets lack systematicity, resulting in insufficient analysis of the conical motion mechanism, which affects flight stability and range.
The projectile's conical motion under static flow was tested, and data processing methods were employed. This included static model-less and static model-with comparative tests to verify the static measurement reliability of the test platform. Subsequently, conical motion with model and reverse conical motion with model tests were conducted to decompose and extract the normal and tangential force components of the model, thereby verifying the dynamic measurement reliability.
This study decomposed and extracted the force sources of the projectile's conical motion, providing a basis for in-depth analysis and laying the foundation for subsequent wind tunnel tests and data processing. It also improved the flight stability of the projectile and the accuracy of range prediction.
Smart Images
Figure CN122062869A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of aircraft aerodynamics and relates to a test measurement and data processing method, specifically a test and data processing method for the conical motion of a projectile under stationary incoming flow. Background Technology
[0002] During flight, a projectile rotates around its longitudinal axis, generating a gyroscopic effect to maintain stable flight. Although the lateral force and yaw moment (Magnus effect) induced by the projectile's rotational motion are relatively small, only 1 / 100 to 1 / 10 of the normal force and pitch moment, the yaw moment always causes the projectile axis to swing out of the plane of attack. Under the influence of disturbances, in addition to rotating around its axis, a spinning projectile also undergoes rotation around its velocity vector at a fixed angle of attack during flight, forming a conical trajectory centered on the velocity vector, known as conical motion.
[0003] When the angle between the projectile axis and the velocity vector remains large, conical motion induces significant drag, resulting in a shorter launch range and increased dispersion. When lateral forces and yaw moments exceed certain limits, phenomena such as "Magnus instability" and "catastrophic yaw" occur, indicating conical motion divergence and flight failure. In the 1960s, the US Nitehawk sounding rocket exhibited nearly 20 instances of divergent conical motion in over 50 flight tests; the Spanish 150mm rocket exhibited conical motion in 9 out of 28 flight tests; and similar conical motion phenomena have been observed in my country's unguided rocket flight tests.
[0004] NASA began studying the aerodynamic characteristics of rotating projectiles in the 1980s and conducted a series of experiments. However, there is limited research on conical motion both domestically and internationally, and corresponding data processing experience is lacking. Therefore, it is of great significance to conduct relevant experiments, decompose and extract the forces acting on projectiles in different directions during conical motion, and streamline the methods and procedures for ground-based conical motion experiments and data processing of projectiles, so as to provide guidance for subsequent force measurement experiments and data processing of projectile rotation-conical motion coupling in wind tunnels. Summary of the Invention
[0005] (a) Technical problems to be solved
[0006] The technical problem to be solved by this invention is: how to provide a method for testing and processing data of the conical motion of a projectile under static flow. The method outlines the process of testing and processing data of the conical motion of a projectile under static flow, providing a strong basis for further in-depth analysis of the force on the conical motion of a projectile.
[0007] (II) Technical Solution
[0008] To solve the above-mentioned technical problems, the present invention provides a method for testing and processing the conical motion of a projectile under static incoming flow, the method comprising the following steps:
[0009] Step 1: Conduct comparative tests of static model-free and static model-with tests based on the projectile-arrow conical motion test platform;
[0010] Step 2: Based on the static test data, process the data to obtain the model gravity and verify the reliability of the static measurement of the test platform;
[0011] Step 3: Based on the fact that the test platform meets the static measurement requirements, conduct the cone dynamic model test and the reverse cone dynamic model test;
[0012] Step 4: Based on the cone motion test data, process the data to obtain the normal and tangential force components of the model other than gravity, and verify the reliability of the dynamic measurement of the test platform.
[0013] In step one, during the static experiment, the model is selected at four positions: top, bottom, left, and right, to verify the accuracy and reliability of the static force measurement in two directions of the test system.
[0014] In step two, the model gravity at the top and bottom positions is obtained by subtracting the normal forces of the balances in the two sets of static tests, while the model gravity at the leftmost and rightmost positions is obtained by subtracting the tangential forces.
[0015] In step three, during the dynamic test of conical motion, the initial position of the model remains consistent, meaning there is no phase difference in the model's motion, which facilitates data post-processing.
[0016] In step four, the centripetal force of the model is obtained by subtracting the gravitational component from the normal force of the balance, and the tangential force of the model is obtained by subtracting the tangential forces of the balance from the forward and reverse rotation experiments.
[0017] The method is based on a projectile cone motion test platform. First, a static test without a model and a static test with a model are conducted. The model gravity can be obtained by subtracting the results, thereby verifying whether the test platform meets the static measurement requirements.
[0018] The method then conducts conical motion + model and reverse conical motion + model tests. Subtracting the tangential measurement results from the balance of the two sets of tests yields the tangential force component of the model excluding gravity. Subtracting the gravity component from the normal measurement results yields the centripetal force component of the model. The model's stress is then compared with the theoretical centripetal force to verify its rationality, laying the foundation for subsequent wind tunnel tests and data processing.
[0019] The proposed method solves the problem of decomposing and extracting different force sources in the conical motion of a projectile, and streamlines the experimental and data processing procedures for the conical motion of a projectile under static flow conditions. This provides a strong foundation for in-depth force analysis of the conical motion of a projectile, and also provides a basis and ideas for subsequent force measurement experiments and data processing of the rotational-conical coupled motion of a projectile in a wind tunnel.
[0020] (III) Beneficial Effects
[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0022] 1. An innovative experimental and data processing method for the conical motion of a projectile under static flow is proposed. Through static and dynamic experiments, the normal and tangential forces of the model are decomposed and extracted, solving the problem of decomposition and extraction of different force sources in the conical motion of the projectile.
[0023] 2. Using the experimental procedure and data processing method described in this paper, force measurement experiments on the conical motion of projectiles and rockets under incoming flow conditions can be carried out in a wind tunnel, thereby collecting aerodynamic data that better reflects real flight conditions and providing technical guidance for further exploration of the mechanism and stability of conical motion. Attached Figure Description
[0024] Figure 1 Flowchart of the test and data processing method for the conical motion of a projectile under stationary flow;
[0025] Figure 2 Schematic diagrams of motion trajectories in static and conical tests;
[0026] Figure 3 The trend of changes in raw data at the lowest and rightmost positions of the static test over time;
[0027] Figure 4 Trends in the original and fitted data of normal force during cone motion tests over time;
[0028] Figure 5 Trends in the original and fitted data of tangential force in the cone motion test over time;
[0029] Figure 6 Statistical results of centripetal force at different conical frequencies. Detailed Implementation
[0030] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.
[0031] To solve the above-mentioned technical problems, the present invention provides a method for testing and processing the conical motion of a projectile under static incoming flow, the method comprising the following steps:
[0032] Step 1: Conduct comparative tests of static model-free and static model-with tests based on the projectile-arrow conical motion test platform;
[0033] Step 2: Based on the static test data, process the data to obtain the model gravity and verify the reliability of the static measurement of the test platform;
[0034] Step 3: Based on the fact that the test platform meets the static measurement requirements, conduct the cone dynamic model test and the reverse cone dynamic model test;
[0035] Step 4: Based on the cone motion test data, process the data to obtain the normal and tangential force components of the model other than gravity, and verify the reliability of the dynamic measurement of the test platform.
[0036] In step one, during the static experiment, the model is selected at four positions: top, bottom, left, and right, to verify the accuracy and reliability of the static force measurement in two directions of the test system.
[0037] In step two, the model gravity at the top and bottom positions is obtained by subtracting the normal forces of the balances in the two sets of static tests, while the model gravity at the leftmost and rightmost positions is obtained by subtracting the tangential forces.
[0038] In step three, during the dynamic test of conical motion, the initial position of the model remains consistent, meaning there is no phase difference in the model's motion, which facilitates data post-processing.
[0039] In step four, the centripetal force of the model is obtained by subtracting the gravitational component from the normal force of the balance, and the tangential force of the model is obtained by subtracting the tangential forces of the balance from the forward and reverse rotation experiments.
[0040] The method is based on a projectile cone motion test platform. First, a static test without a model and a static test with a model are conducted. The model gravity can be obtained by subtracting the results, thereby verifying whether the test platform meets the static measurement requirements.
[0041] The method then conducts conical motion + model and reverse conical motion + model tests. Subtracting the tangential measurement results from the balance of the two sets of tests yields the tangential force component of the model excluding gravity. Subtracting the gravity component from the normal measurement results yields the centripetal force component of the model. The model's stress is then compared with the theoretical centripetal force to verify its rationality, laying the foundation for subsequent wind tunnel tests and data processing.
[0042] The proposed method solves the problem of decomposing and extracting different force sources in the conical motion of a projectile, and streamlines the experimental and data processing procedures for the conical motion of a projectile under static flow conditions. This provides a strong foundation for in-depth force analysis of the conical motion of a projectile, and also provides a basis and ideas for subsequent force measurement experiments and data processing of the rotational-conical coupled motion of a projectile in a wind tunnel.
[0043] Example 1
[0044] This implementation example Figure 1 As shown, the provided method for testing and processing the conical motion of a projectile under static flow includes the following steps:
[0045] Static tests mainly include two types: static without a model and static with a model. The only difference between the two is whether the model is mounted on the balance support. There are four initial parking positions for the model, which, viewed from back to front, are the top, bottom, leftmost, and rightmost. Figure 2 As shown. This step is mainly to verify whether the force measured by the balance is 0 when there is no model; whether the force measured by the balance is equal to the weight of the model when there is a model; and whether the force measured by the balance in different directions at different locations is consistent.
[0046] The results of the static force measurement test are as follows Figure 3 As shown, when there is no static model, the force measurement results of the balance at different initial parking positions are all 0, indicating that the balance has been calibrated to zero. When there is a static model, the force measurement result of the balance in the y-direction at the bottom position is basically consistent with the gravity, indicating that the static force measurement result in the y-direction of the balance is highly reliable. Similarly, the force measurement result in the z-direction at the rightmost position is basically consistent with the gravity, indicating that the static force measurement result in the z-direction of the balance is highly reliable.
[0047] Dynamic tests mainly include forward conical motion tests and reverse conical motion tests. The forward and reverse directions are defined as follows: Figure 2 As shown. For the force balance results, a series of data processing steps, including filtering, initial phase determination, and gravity subtraction, are required to obtain the force components in different directions. The filtering process mainly includes Fourier transforming the initial force signal, designing a filter (a bandpass filter is used in this paper), processing the signal in the frequency domain using the filter, and performing an inverse Fourier transform on the processed signal to obtain the time-domain filtered force signal. The initial phase determination process includes performing Fourier transforms on the filtered force signal and the reference signal, calculating the phase at different frequencies, obtaining the phase difference between the force signal and the reference signal at the dominant frequency, and thus determining the initial phase of the filtered force signal. The gravity subtraction process requires calculating the time-varying trends of gravity in the normal and tangential directions based on the initial phase of the filtered force signal, and then calculating the difference between the filtered force signal and the gravity component to obtain the centripetal force of the model and the tangential force after gravity subtraction.
[0048] The model's cone-shaped normal force, normal force fitting results, and centripetal force results are as follows: Figure 4 As shown, the theoretical value of the centripetal force during the model's constant-frequency circular motion is 4mπ. 2 f 2 r, the theoretical force on the model when it moves to the top is 4mπ. 2 f 2r+mg, with mg-4mπ at the bottom. 2 f 2 r, ultimately leading to Figure 4 The peak-to-peak value of the normal force variation curve of the model is almost equal to Figure 3 The model shown has a force twice that of gravity, and the centripetal force result remains almost constant over time, which fully demonstrates the reliability of the dynamic force measurement in the y-direction of the cone-shaped force measurement platform.
[0049] The model's forward and reverse cone dynamic tangential forces, tangential force fitting results, and tangential force results after deducting gravity are as follows: Figure 5 As shown, since the experiment was conducted under windless conditions and the tangential velocity remained constant, the theoretical value of the tangential force on the model after deducting gravity was 0. The theoretical force on the model at the leftmost position was 0-mg, and at the rightmost position it was mg+0, ultimately leading to... Figure 5 The peak-to-peak value of the model's tangential force variation curve is almost equal to Figure 3 The model shown has twice the gravity, and the tangential force is almost zero after deducting gravity, which fully demonstrates the reliability of the z-axis dynamic force measurement of the cone-shaped force measurement platform.
[0050] Statistical results of centripetal force of the model at different conical frequencies are as follows: Figure 6 As shown, the x-axis represents the square of the conical frequency, and the y-axis represents the centripetal force. It can be observed that the centripetal force and the square of the conical frequency exhibit a good linear relationship, i.e., F = 4mπ. 2 r×f 2 ,and Figure 4 The analysis results are consistent, fully demonstrating the reliability of the cone-shaped force measuring platform in dynamic force measurement at different frequencies.
[0051] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for testing and processing data on the conical motion of a projectile under stationary incoming flow, characterized in that, The method includes the following steps: Step 1: Conduct comparative tests of static model-free and static model-with tests based on the projectile-arrow conical motion test platform; Step 2: Based on the static test data, process the data to obtain the model gravity and verify the reliability of the static measurement of the test platform; Step 3: Based on the fact that the test platform meets the static measurement requirements, conduct the cone dynamic model test and the reverse cone dynamic model test; Step 4: Based on the cone motion test data, process the data to obtain the normal and tangential force components of the model other than gravity, and verify the reliability of the dynamic measurement of the test platform.
2. The method for testing and processing the conical motion of a projectile under stationary incoming flow as described in claim 1, characterized in that, In step one, during the static experiment, the model is selected at four positions: top, bottom, left, and right, in order to verify the accuracy and reliability of the static force measurement in two directions of the test system.
3. The method for testing and processing the conical motion of a projectile under stationary incoming flow as described in claim 1, characterized in that, In step two, the model gravity at the top and bottom positions is obtained by subtracting the normal forces of the balance from the two sets of static tests, while the model gravity at the leftmost and rightmost positions is obtained by subtracting the tangential forces.
4. The method for testing and processing the conical motion of a projectile under stationary incoming flow as described in claim 1, characterized in that, In step three, during the dynamic test of conical motion, the initial position of the model remains consistent, meaning there is no phase difference in the model's motion, which facilitates data post-processing.
5. The method for testing and processing the conical motion of a projectile under stationary incoming flow as described in claim 1, characterized in that, In step four, the centripetal force of the model is obtained by subtracting the gravitational component from the normal force of the balance, and the tangential force of the model is obtained by subtracting the tangential forces of the balance from the forward and reverse rotation experiments.
6. The method for testing and processing the conical motion of a projectile under stationary incoming flow as described in claim 1, characterized in that, The method is based on a projectile cone motion test platform. First, a static test without a model and a static test with a model are conducted. The model gravity can be obtained by subtracting the results, thereby verifying whether the test platform meets the static measurement requirements.
7. The method for testing and processing the conical motion of a projectile under stationary incoming flow as described in claim 6, characterized in that, The method then conducts conical motion + model and reverse conical motion + model tests. Subtracting the tangential measurement results from the balance of the two sets of tests yields the tangential force component of the model excluding gravity. Subtracting the gravity component from the normal measurement results yields the centripetal force component of the model. The model's stress is then compared with the theoretical centripetal force to verify its rationality, laying the foundation for subsequent wind tunnel tests and data processing.
8. The method for testing and processing the conical motion of a projectile under stationary incoming flow as described in claim 7, characterized in that, The proposed method solves the problem of decomposing and extracting different force sources in the conical motion of a projectile, and streamlines the experimental and data processing procedures for the conical motion of a projectile under static flow conditions. This provides a strong foundation for in-depth force analysis of the conical motion of a projectile, and also provides a basis and ideas for subsequent force measurement experiments and data processing of the rotational-conical coupled motion of a projectile in a wind tunnel.
9. The method for testing and processing the conical motion of a projectile under stationary incoming flow as described in claim 8, characterized in that, The method innovatively and ingeniously achieves the decomposition and extraction of the normal and tangential forces of the model through static and dynamic experiments, solving the problem of decomposition and extraction of different force sources in the conical motion of the projectile.
10. The method for testing and processing the conical motion of a projectile under stationary incoming flow as described in claim 9, characterized in that, Using this method, force measurement tests of projectile conical motion under incoming flow conditions can be carried out in a wind tunnel, thereby collecting aerodynamic data that better reflects real flight conditions, and providing technical guidance for further exploration of the mechanism and stability of conical motion.