Helicopter floatability quick estimation method
Patent Information
- Application Number
- CN202510418144.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2026-10-16
AI Technical Summary
以往的一般做法是仅进行浮力设计，留出一定的浮力余量，然后通过缩比模型的水池试验直接进行验证，但这种方法缺少了稳定性分析过程，漂浮能力的评估全依赖于试验，周期长、代价高，且受限于水池造波能力、直升机模型的尺寸以及重量调配等因素，对于有些型号并不适用；近年来也有通过水动力计算软件进行仿真计算的，这种方法需要精细的网格模型和复杂的算法，分析周期较长，在方案设计之初难以快速给出结果
[0029] This invention proposes a rapid method for estimating the floating stability of helicopters. Based on the target helicopter's floating capability requirements, a reference helicopter similar in floating capability, helicopter configuration, and floating system configuration is selected. Static stability calculations are performed on the reference helicopter, and weight independence is applied to obtain a criterion for rapid estimation of floating capability. Then, by comparing the target helicopter's static stability parameters with the criterion, the sea state class in which the target helicopter can float can be quickly determined. This method avoids reliance on pool tests and complex mathematical algorithms in the early stages of scheme design, reducing the difficulty, cycle, and complexity of calculation and evaluation, and overcoming the efficiency shortcomings of previous methods, thus providing support for rapid scheme iteration.
Smart Images
Figure CN122926685A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of flight mechanics technology, and in particular relates to a rapid estimation method for the floating stability of helicopters. Background Technology
[0002] Shipborne helicopters and helicopters used on water need to be able to float on water so that they can remain upright on the surface after an emergency landing, providing conditions for the escape of personnel. The dynamics of floating on water determine the safety of helicopter operations on water. With the development of the helicopter industry, the configuration using rigid floats and ship-like fuselages is becoming less common. Currently, most helicopter maritime rescue systems use inflatable emergency flotation systems to provide the helicopter with emergency floating capabilities.
[0003] During the engineering design phase, it is necessary to evaluate the buoyancy capability after installing the emergency flotation system. The traditional approach is to only perform buoyancy design, leaving a certain buoyancy margin, and then directly verify it through tank tests on a scaled-down model. However, this method lacks a stability analysis process, and the evaluation of buoyancy capability relies entirely on testing, which is time-consuming, costly, and limited by factors such as the wave-generating capacity of the tank, the size of the helicopter model, and weight distribution, making it unsuitable for some models. In recent years, simulation calculations using hydrodynamic software have also been used. This method requires a detailed mesh model and complex algorithms, resulting in a long analysis cycle and making it difficult to provide results quickly at the initial design stage. Summary of the Invention
[0004] The present invention aims to propose an estimation method suitable for rapid evaluation of buoyancy capability in the early stages of a project, thereby improving the efficiency of buoyancy capability evaluation. At the same time, this method is based on the test and usage experience of similar models, and has high reliability, which can provide support for the rapid and accurate iteration of helicopter buoyancy schemes.
[0005] To achieve the above objectives, the present invention employs the following technical solution.
[0006] A method for rapid estimation of helicopter floating stability, the method comprising:
[0007] S1, acquire wave height data, 3D model and weight center of gravity data of the reference machine floating;
[0008] S2. Based on the three-dimensional shape and weight center of gravity data of the floating reference machine, calculate the relationship curve between the lateral restoring moment and the roll angle of the reference machine in still water.
[0009] S3. Based on the relationship curve between the lateral restoring torque and the roll angle of the reference machine in still water, determine the buoyancy criterion of the reference machine. The buoyancy criterion includes: the vanishing angle of stability of the reference machine and the integral area of the restoring torque factor.
[0010] S4, acquire the target machine's three-dimensional shape and weight center of gravity data;
[0011] S5. Based on the target aircraft's three-dimensional shape and weight center of gravity data, calculate the relationship curve between the target aircraft's lateral restoring moment and roll angle in still water.
[0012] S6. Based on the relationship curve between the lateral restoring moment and the roll angle of the target aircraft in still water, calculate the stability parameters of the target aircraft. The stability parameters include: the stability vanishing angle of the target aircraft and the integral area of the restoring moment factor.
[0013] S7, when the vanishing angle of the target aircraft is greater than that of the reference aircraft, and the integral area of the restoring moment factor of the target aircraft is greater than that of the integral area of the restoring moment factor of the reference aircraft, the target aircraft has the floating capability corresponding to the wave height data of the floating capability criterion.
[0014] Furthermore, in S1, the reference aircraft is a helicopter with a shape and floating system configuration similar to the target aircraft;
[0015] Similarity to the target machine in shape means that when the reference machine is enlarged or reduced proportionally to match the target machine in lateral dimensions, the error in longitudinal and vertical dimensions is no more than 10%.
[0016] The configuration of the floating system of the reference aircraft is similar to that of the target aircraft: the relative position of the floating system of the reference aircraft on the aircraft is such that the lateral position error and the vertical position error are both no more than 10% compared with the relative position of the floating system of the target aircraft on the aircraft.
[0017] Furthermore, in S1, the buoyancy of the reference machine was verified through a water tank test.
[0018] Furthermore, S3 specifically refers to:
[0019] Divide the lateral restoring torque by the weight indifference coefficient to obtain the lateral restoring torque factor value that is independent of weight, and obtain the relationship curve between the restoring torque factor and the roll angle.
[0020] Based on the relationship curve between the restoring torque factor and the roll angle, the vanishing stability angle is extracted; the vanishing stability angle refers to the roll angle corresponding to the restoring torque factor being zero.
[0021] On the curve relating the restoring moment factor to the roll angle, the integral area of the restoring moment factor is calculated with the static equilibrium point as the starting point and the vanishing stability angle as the ending point. The vanishing stability angle and the integral area of the restoring moment factor of the reference machine are used as the floating stability criteria under the corresponding wave height data.
[0022] Furthermore, the weight independence coefficient is the 4 / 3 power of the reference machine weight.
[0023] Furthermore, S6 specifically refers to:
[0024] Divide the lateral restoring torque by the weight indifference coefficient to obtain the lateral restoring torque factor value that is independent of weight, and obtain the relationship curve between the restoring torque factor and the roll angle.
[0025] Based on the relationship curve between the restoring torque factor and the roll angle, the vanishing stability angle is extracted; the vanishing stability angle refers to the roll angle corresponding to the restoring torque factor being zero.
[0026] On the curve relating the restoring torque factor to the roll angle, calculate the integral area of the restoring torque factor starting from the static equilibrium point and ending at the vanishing stability angle. Use the vanishing stability angle and the integral area of the restoring torque factor of the target aircraft as the stability parameters of the target aircraft.
[0027] Furthermore, after S4 and before S5, the method further includes:
[0028] The target aircraft's float volume is allocated so that its waterline is at the same vertical relative position as the reference aircraft.
[0029] This invention proposes a rapid method for estimating the floating stability of helicopters. Based on the target helicopter's floating capability requirements, a reference helicopter similar in floating capability, helicopter configuration, and floating system configuration is selected. Static stability calculations are performed on the reference helicopter, and weight independence is applied to obtain a criterion for rapid estimation of floating capability. Then, by comparing the target helicopter's static stability parameters with the criterion, the sea state class in which the target helicopter can float can be quickly determined. This method avoids reliance on pool tests and complex mathematical algorithms in the early stages of scheme design, reducing the difficulty, cycle, and complexity of calculation and evaluation, and overcoming the efficiency shortcomings of previous methods, thus providing support for rapid scheme iteration. Attached Figure Description
[0030] Figure 1 This is a flowchart illustrating a rapid estimation method for helicopter floating stability provided in an embodiment of the present invention. Detailed Implementation
[0031] The technical solution of the present invention will be implemented below with reference to the accompanying drawings.
[0032] This invention provides a method for rapidly estimating the floating stability of a helicopter, such as... Figure 1 As shown, the method includes:
[0033] S1, acquire wave height data, 3D model and weight center of gravity data of the reference machine floating;
[0034] S2. Based on the three-dimensional shape and weight center of gravity data of the floating reference machine, calculate the relationship curve between the lateral restoring moment and the roll angle of the reference machine in still water.
[0035] S3. Based on the relationship curve between the lateral restoring torque and the roll angle of the reference machine in still water, determine the buoyancy criterion of the reference machine. The buoyancy criterion includes: the vanishing angle of stability of the reference machine and the integral area of the restoring torque factor.
[0036] S4, acquire the target machine's three-dimensional shape and weight center of gravity data;
[0037] S5. Based on the target aircraft's three-dimensional shape and weight center of gravity data, calculate the relationship curve between the target aircraft's lateral restoring moment and roll angle in still water.
[0038] S6. Based on the relationship curve between the lateral restoring moment and the roll angle of the target aircraft in still water, calculate the stability parameters of the target aircraft. The stability parameters include: the stability vanishing angle of the target aircraft and the integral area of the restoring moment factor.
[0039] S7, when the vanishing angle of the target aircraft is greater than that of the reference aircraft, and the integral area of the restoring moment factor of the target aircraft is greater than that of the integral area of the restoring moment factor of the reference aircraft, the target aircraft has the floating capability corresponding to the wave height data of the floating capability criterion.
[0040] In S1, the reference aircraft is a helicopter that is similar to the target aircraft in shape and floating system configuration;
[0041] Similarity to the target machine in shape means that when the reference machine is enlarged or reduced proportionally to match the target machine in lateral dimensions, the error in longitudinal and vertical dimensions is no more than 10%.
[0042] The configuration of the floating system of the reference aircraft is similar to that of the target aircraft: the relative position of the floating system of the reference aircraft on the aircraft is such that the lateral position error and the vertical position error are both no more than 10% compared with the relative position of the floating system of the target aircraft on the aircraft.
[0043] In S1, the buoyancy of the reference machine was verified through a water tank test.
[0044] S3 specifically refers to:
[0045] Divide the lateral restoring torque by the weight indifference coefficient to obtain the lateral restoring torque factor value that is independent of weight, and obtain the relationship curve between the restoring torque factor and the roll angle.
[0046] Based on the relationship curve between the restoring torque factor and the roll angle, the vanishing stability angle is extracted; the vanishing stability angle refers to the roll angle corresponding to the restoring torque factor being zero.
[0047] On the curve relating the restoring moment factor to the roll angle, the integral area of the restoring moment factor is calculated with the static equilibrium point as the starting point and the vanishing stability angle as the ending point. The vanishing stability angle and the integral area of the restoring moment factor of the reference machine are used as the floating stability criteria under the corresponding wave height data.
[0048] The weight independence coefficient is the 4 / 3 power of the reference machine weight.
[0049] S6, specifically:
[0050] Divide the lateral restoring torque by the weight indifference coefficient to obtain the lateral restoring torque factor value that is independent of weight, and obtain the relationship curve between the restoring torque factor and the roll angle.
[0051] Based on the relationship curve between the restoring torque factor and the roll angle, the vanishing stability angle is extracted; the vanishing stability angle refers to the roll angle corresponding to the restoring torque factor being zero.
[0052] On the curve relating the restoring torque factor to the roll angle, calculate the integral area of the restoring torque factor starting from the static equilibrium point and ending at the vanishing stability angle. Use the vanishing stability angle and the integral area of the restoring torque factor of the target aircraft as the stability parameters of the target aircraft.
[0053] The method further includes the following steps after S4 and before S5:
[0054] The target aircraft's float volume is allocated so that its waterline is at the same vertical relative position as the reference aircraft.
[0055] This invention proposes a rapid estimation method for helicopter floating stability to address the difficulties in assessing the floating capacity of helicopters and their floating systems during the initial design phase: firstly, water tank testing is not feasible in the early stages of design; secondly, grid-based hydrodynamic analysis software is time-consuming and cannot provide timely conclusions. This invention relates to the field of helicopter technology.
[0056] The technical solution adopted in this invention is: to provide a rapid estimation method for helicopter floating stability, the process of which is shown in the appendix. Figure 1 It includes the following steps:
[0057] Step 1: Collect reference aircraft data to determine the buoyancy of similar configurations. Based on the design characteristics of the target aircraft, collect reference aircraft that are similar in shape, center of gravity, and buoyancy system configuration, and obtain the reference aircraft's maximum buoyancy, 3D model, and center of gravity data. The reference aircraft should have its buoyancy verified through tank testing, preferably through actual flight testing, to provide background data for evaluating the target aircraft's buoyancy.
[0058] Step Two: Determine the buoyancy criterion based on the reference aircraft data. Using the reference aircraft's shape, weight, and center of gravity data as basic inputs, calculate the reference aircraft's stability data in still water, including longitudinal and lateral stability data. Then, divide the restoring torque by the weight to the power of 4 / 3 to obtain the restoring torque factor value, which is independent of weight, and plot the restoring torque factor curve. Finally, extract the vanishing angle of stability from the restoring torque factor curve, and integrate to obtain the area under the curve. Use the vanishing angle of stability and the integrated area as the buoyancy stability criterion for the corresponding sea state.
[0059] Step 3: Calculate the restoring moment of the target aircraft design. Based on the target aircraft's buoyancy, waterline height, buoyancy distribution, and its weight and center of gravity data, calculate its stability in still water, i.e., the restoring moment curve;
[0060] Step 4: Calculate the weight-independent stability data of the target machine. Divide the values of each point on the restoring torque curve of the target machine by the weight to the power of 4 / 3 to obtain the restoring torque factor values that are independent of the weight. Extract the vanishing angle of stability and integrate to obtain the area under the curve data.
[0061] Step 5: Criterion passability test to determine the target aircraft's floating sea state level. After the above four steps, the integral area of the restoring moment factor, the vanishing angle of stability, and the corresponding criterion data are obtained. If the calculated result is greater than the criterion, the test is passed, and the target aircraft has the ability to float in the sea state level corresponding to the criterion. If the test fails, the process returns to normal, and the floating plan needs to be redesigned.
[0062] This invention proposes a rapid method for estimating the floating stability of helicopters. Based on the target helicopter's floating capability requirements, a reference helicopter similar in floating capability, helicopter configuration, and floating system configuration is selected. Static stability calculations are performed on the reference helicopter, and weight independence is applied to obtain a criterion for rapid estimation of floating capability. Then, by comparing the target helicopter's static stability parameters with the criterion, the sea state class in which the target helicopter can float can be quickly determined. This method avoids reliance on pool tests and complex mathematical algorithms in the early stages of scheme design, reducing the difficulty, cycle, and complexity of calculation and evaluation, and overcoming the efficiency shortcomings of previous methods, thus providing support for rapid scheme iteration.
Claims
1. A method for rapid estimation of helicopter floating stability, characterized in that, The method includes: S1, acquire wave height data, 3D model and weight center of gravity data of the reference floating machine; S2. Based on the three-dimensional shape and weight center of gravity data of the floating reference machine, calculate the relationship curve between the lateral restoring moment and the roll angle of the reference machine in still water. S3. Based on the relationship curve between the lateral restoring torque and the roll angle of the reference machine in still water, determine the buoyancy criterion of the reference machine. The buoyancy criterion includes: the vanishing angle of stability of the reference machine and the integral area of the restoring torque factor. S4, acquire the target machine's three-dimensional shape and weight center of gravity data; S5. Based on the target aircraft's three-dimensional shape and weight center of gravity data, calculate the relationship curve between the target aircraft's lateral restoring moment and roll angle in still water. S6. Based on the relationship curve between the lateral restoring moment and the roll angle of the target aircraft in still water, calculate the stability parameters of the target aircraft. The stability parameters include: the stability vanishing angle of the target aircraft and the integral area of the restoring moment factor. S7, when the vanishing angle of the target aircraft is greater than that of the reference aircraft, and the integral area of the restoring moment factor of the target aircraft is greater than that of the integral area of the restoring moment factor of the reference aircraft, the target aircraft has the floating capability corresponding to the wave height data of the floating capability criterion.
2. The rapid estimation method for helicopter floating stability according to claim 1, characterized in that, In S1, the reference aircraft is a helicopter that is similar to the target aircraft in shape and floating system configuration; Similarity to the target machine in shape means that when the reference machine is enlarged or reduced proportionally to match the target machine in lateral dimensions, the error in longitudinal and vertical dimensions is no more than 10%. The configuration of the floating system of the reference aircraft is similar to that of the target aircraft: the relative position of the floating system of the reference aircraft on the aircraft is such that the lateral position error and the vertical position error are both no more than 10% compared with the relative position of the floating system of the target aircraft on the aircraft.
3. The method for rapid estimation of helicopter floating stability according to claim 1, characterized in that, In S1, the buoyancy of the reference machine was verified through a water tank test.
4. The method for rapid estimation of helicopter floating stability according to claim 1, characterized in that, S3 specifically refers to: Divide the lateral restoring torque by the weight indifference coefficient to obtain the lateral restoring torque factor value that is independent of weight, and obtain the relationship curve between the restoring torque factor and the roll angle. Based on the relationship curve between the restoring torque factor and the roll angle, the vanishing stability angle is extracted; the vanishing stability angle refers to the roll angle corresponding to the restoring torque factor being zero. On the curve relating the restoring moment factor to the roll angle, the integral area of the restoring moment factor is calculated with the static equilibrium point as the starting point and the vanishing stability angle as the ending point. The vanishing stability angle and the integral area of the restoring moment factor of the reference machine are used as the floating stability criteria under the corresponding wave height data.
5. The rapid estimation method for helicopter floating stability according to claim 4, characterized in that, The weight independence coefficient is the 4 / 3 power of the reference machine weight.
6. The rapid estimation method for helicopter floating stability according to claim 1, characterized in that, S6, specifically: Divide the lateral restoring torque by the weight indifference coefficient to obtain the lateral restoring torque factor value that is independent of weight, and obtain the relationship curve between the restoring torque factor and the roll angle. Based on the relationship curve between the restoring torque factor and the roll angle, the vanishing stability angle is extracted; the vanishing stability angle refers to the roll angle corresponding to the restoring torque factor being zero. On the curve relating the restoring torque factor to the roll angle, calculate the integral area of the restoring torque factor starting from the static equilibrium point and ending at the vanishing stability angle. Use the vanishing stability angle and the integral area of the restoring torque factor of the target aircraft as the stability parameters of the target aircraft.
7. The rapid estimation method for helicopter floating stability according to claim 1, characterized in that, The method further includes the following steps after S4 and before S5: The target aircraft's float volume is allocated so that its waterline is at the same vertical relative position as the reference aircraft.
8. A rapid estimation device for helicopter floating stability, characterized in that, The apparatus is used to perform the method as described in any one of claims 1-7.