CN-122021377-A - Method and system for calculating dynamics of take-off and landing process of seaplane adapting to high sea conditions

CN122021377ACN 122021377 ACN122021377 ACN 122021377ACN-122021377-A

Abstract

The invention provides a method and a system for calculating dynamics in a take-off and landing process of a water plane, which are suitable for high sea conditions, wherein hydrodynamic test data of a ship-shaped fuselage at the bottom of the water plane are acquired in real time, a body coordinate system and a ground coordinate system are established, then a height compensation model and a posture compensation model are established based on wave heights so as to obtain vertical distances and pitch angles after wave influence correction, a specific calculation method is adopted to calculate the infiltration area of the current moment after wave influence, and finally the infiltration area after wave influence is introduced on the basis of a full-quantity motion equation consisting of a centroid dynamics equation, a centroid kinematics equation, a rotation dynamics equation and a rotation kinematics equation, so that an improved centroid dynamics equation, a centroid kinematics equation, a rotation dynamics equation and a rotation kinematics equation are established, and further flight state parameters are calculated, so that real-time dynamic analysis of the take-off and landing process of the water plane under the high sea conditions is realized, and the method has remarkable rapidity, instantaneity and accuracy.

Inventors

Mai Linrui
LIU GANG
Sang Tengjiao
Ji Runjie
ZHAO LUJUN

Assignees

北京航空航天大学
中国特种飞行器研究所

Dates

Publication Date: 20260512
Application Date: 20251212

Claims (8)

1. The method for calculating dynamics of the take-off and landing process of the water plane suitable for the high sea conditions is characterized by comprising the following steps of: The method comprises the steps of acquiring water dynamic test data of a ship body at the bottom of a water plane in real time, wherein the water dynamic test data comprise wave height, pitch angle, ship body inclined lift angle, vertical distance from a broken-order point of the ship body to a horizontal plane and bilge width of the ship body; The method comprises the steps of establishing a ground coordinate system by taking any point on a sea level as an origin, taking an initial motion direction of an airplane as a longitudinal axis, taking a direction parallel to the starboard of the airplane as a transverse axis and taking a geocenter as a vertical axis, acquiring an airplane centroid coordinate positioned under the ground coordinate system, respectively establishing a height compensation model and a posture compensation model based on an abscissa in the centroid coordinate and the wave height at the current moment, inputting a vertical distance from a breaking point to the horizontal plane at the current moment into the height compensation model to obtain a vertical distance corrected by wave influence; Calculating the mean immersion length of the body based on the keel line immersion length and the bilge line immersion length, then calculating the immersion length of the body based on the mean immersion length of the body and the bilge width, correcting the immersion length-width ratio of the body by adopting an empirical formula method based on hydrodynamic test data to obtain the corrected immersion length-width ratio, and calculating the immersion area of the water plane affected by waves at the current moment according to the corrected immersion length-width ratio and the bilge width; And a step of real-time analysis in the take-off and landing process, which is to introduce the wave-affected infiltration area on the basis of a full-volume motion equation composed of a barycenter dynamics equation, a barycenter kinematics equation, a rotation dynamics equation and a rotation kinematics equation so as to update the original infiltration area which is not affected by waves in the full-volume motion equation, thereby obtaining an updated full-volume motion equation, and calculate flight state parameters based on the updated full-volume motion equation so as to realize real-time dynamic analysis in the take-off and landing process of the water plane under the high sea condition.
2. The method for calculating dynamics of take-off and landing process of a water craft adapting to high sea conditions according to claim 1, wherein a body coordinate system is established by taking a plane centroid as an origin, a nose direction of the plane as a longitudinal axis, a starboard direction of the plane as a transverse axis and a bottom direction of the plane as a vertical axis, and the flight state parameters comprise plane linear speeds in the longitudinal axis, the transverse axis and the vertical axis directions in the body coordinate system, plane angular speeds in the longitudinal axis, the transverse axis and the vertical axis directions in the body coordinate system, plane centroid positions in the longitudinal axis, the transverse axis and the vertical axis directions in the ground coordinate system, rolling angles, pitch angles and yaw angles.
3. The method according to claim 2, wherein in the step of analyzing the take-off and landing process in real time, calculating the flight state parameters based on the updated full-quantity motion equation comprises calculating the aircraft centroid positions in the longitudinal, transverse and vertical axis directions in the ground coordinate system, the aircraft linear speeds and the aircraft angular speeds, the roll angle, the pitch angle and the yaw angle in the longitudinal, transverse and vertical axis directions in the body coordinate system based on the updated centroid dynamics equation, the updated centroid kinematics equation, the rotational dynamics equation and the rotational kinematics equation.
4. The method for dynamically calculating the take-off and landing process of the seaplane adapting to the high sea conditions according to claim 2, wherein the calculated flight state parameters are optimized by adopting a real-time feedback control algorithm to obtain the optimized flight state parameters so as to realize real-time dynamic analysis of the take-off and landing process of the seaplane under the high sea conditions.
5. A dynamics calculation system of a take-off and landing process of a water plane adapting to high sea conditions is characterized by comprising a data acquisition module, a height and posture correction module, an infiltration area calculation module and a real-time analysis module of the take-off and landing process which are connected in sequence, The data acquisition module is used for acquiring the water movement test data of the ship-shaped fuselage at the bottom of the water plane in real time, wherein the water movement test data comprise wave height, pitch angle, ship body inclined lift angle, vertical distance from a broken-order point of the ship-shaped fuselage to a horizontal plane and bilge width of the ship-shaped fuselage; The elevation and attitude correction module is used for establishing a ground coordinate system by taking any point on the sea level as an origin, the initial motion direction of the aircraft as a longitudinal axis, the starboard of the aircraft as a transverse axis and the direction parallel to the sea level as a vertical axis, acquiring the barycenter coordinate of the aircraft under the ground coordinate system, respectively establishing an elevation compensation model and an attitude compensation model based on the abscissa in the barycenter coordinate and the wave height at the current moment, inputting the vertical distance from the breaking point to the horizontal plane at the current moment into the elevation compensation model to obtain the vertical distance corrected by wave influence; The infiltration area calculation module is used for calculating the infiltration length of the keel line of the water plane according to the corrected pitch angle and the corrected vertical distance; calculating the average immersion length of the fuselage based on the immersion length of the keel line and the immersion length of the bilge line, calculating the immersion length of the fuselage according to the average immersion length of the fuselage and the bilge width, correcting the immersion length-width ratio of the fuselage by adopting an empirical formula based on hydrodynamic test data to obtain the corrected immersion length-width ratio, and calculating the immersion area of the water plane affected by waves at the current moment according to the corrected immersion length-width ratio and the bilge width; The real-time analysis module for the take-off and landing process introduces the wave-affected infiltration area on the basis of the full-volume motion equation consisting of the barycenter dynamics equation, the barycenter kinematics equation, the rotation dynamics equation and the rotation kinematics equation to update the original infiltration area which is not affected by the wave in the full-volume motion equation, so as to obtain an updated full-volume motion equation, and calculates flight state parameters based on the updated full-volume motion equation, so that the real-time dynamic analysis of the take-off and landing process of the water plane under the high sea condition is realized.
6. The system of claim 5, further comprising a body coordinate system established with an origin of a mass center of the airplane, a longitudinal axis of a nose direction of the airplane, a transverse axis of a starboard direction of the airplane, and a vertical axis of a bottom of the airplane, wherein the flight state parameters include linear velocities of the airplane in the longitudinal, transverse, and vertical axes directions in the body coordinate system, angular velocities of the airplane in the longitudinal, transverse, and vertical axes directions in the body coordinate system, and positions, roll angles, pitch angles, and yaw angles of the mass center of the airplane in the longitudinal, transverse, and vertical axes directions in the ground coordinate system.
7. The system of claim 6, wherein the real-time analysis module for taking off and landing process calculates the flight state parameters based on the updated full motion equation, and the method comprises calculating the aircraft centroid positions in the longitudinal, transverse and vertical axes in the ground coordinate system, the aircraft linear and angular speeds, roll angle, pitch angle and yaw angle in the longitudinal, transverse and vertical axes in the body coordinate system based on the updated centroid dynamics equation, the updated centroid kinematics equation, the updated rotational dynamics equation and the updated rotational kinematics equation.
8. The system for dynamically calculating the take-off and landing process of the seaplane adapting to the high sea conditions according to claim 6, wherein a real-time feedback control algorithm is adopted to optimize the flight state parameters, so as to obtain the optimized flight state parameters, and further realize real-time dynamic analysis of the take-off and landing process of the seaplane under the high sea conditions.

Description

Method and system for calculating dynamics of take-off and landing process of seaplane adapting to high sea conditions Technical Field The invention relates to the technical field of aviation engineering, in particular to a method and a system for calculating dynamics of a take-off and landing process of a water plane, which are suitable for high sea conditions. Background A water plane is used as an aircraft capable of taking off and landing on the water surface, and the shape design of the water plane needs to consider not only aerodynamic performance, but also hydrodynamic performance of a ship body. This is because a seaplane is affected by various factors such as wind, waves, currents, etc. during take-off and landing, which can significantly affect the stability of the motion, structural strength, and hydrodynamic performance of the plane. In order to ensure that the seaplane can safely take off and land under various sea conditions, students have conducted a great deal of research, and mainly focus on 1) hydrodynamic tests, wherein the traditional research method mainly relies on the hydrodynamic tests, and researches the hydrodynamic performance, the movement stability and the structural strength of the airplane by simulating the water surface sliding and taking off and landing processes under different sea conditions. Although the tests can provide more accurate data, the cost of financial resources and material resources is huge, and the test period is longer. 2) Computational Fluid Dynamics (CFD) method CFD method is becoming an important means of studying hydrodynamic performance of a seaplane with the development of computer technology. The CFD method can accurately calculate the hydrodynamic performance of the aircraft under different sea conditions through numerical simulation. However, CFD methods are time-consuming to calculate, require a lot of computational resources, and are difficult to meet the real-time requirements of flight simulation. 3) The low sea condition research is that the taking-off and landing performance of the water plane under the low sea condition is fully researched at present, and related models and algorithms are relatively mature. These studies provide theoretical support for safe take-off and landing of a seaplane under calm sea conditions. However, previous discussion of the area of infiltration during modeling of the hydroplane dynamics model generally approximates that the water surface is a calm water surface, and this assumption is appropriate at low sea conditions because the effects of waves are small and negligible. 4) High sea condition research, however, the research on the take-off and landing performance of the water plane under the high sea condition is still insufficient. The environmental factors such as wind and wave currents under high sea conditions are more complex, and higher requirements are put on the hydrodynamic performance and the motion stability of the aircraft. The existing hydrodynamic test and CFD method have limited applicability under high sea conditions, and are difficult to meet the requirement of real-time calculation. Particularly in high sea conditions, the peaks and wavelengths are large and are not negligible even at the scale of the aircraft. Therefore, the traditional method for approximating the infiltration area based on the calm water surface is not applicable under the high sea condition, and the infiltration area of the aircraft needs to be dynamically calculated by combining the wave condition so as to more accurately reflect the hydrodynamic characteristics of the aircraft under the high sea condition. Therefore, although the existing research method solves the take-off and landing problems of the water plane under low sea conditions to a certain extent, the method still has the following defects that 1) the hydrodynamic test consumes a large amount of financial resources and material resources and has long test period, and the requirements of high efficiency and low cost in the pre-research process of the design of the plane are difficult to meet. 2) The CFD method can provide accurate calculation results, but the calculation time is long, a large amount of calculation resources are needed, and the requirement of flight simulation on calculation instantaneity is difficult to meet. 3) The adaptability of the high sea state is insufficient, the existing research is mainly focused on the low sea state, the research on the take-off and landing performance of the water plane under the high sea state is insufficient, and a dynamics model and a real-time resolving method which are suitable for the high sea state are lacked. In particular, the static approximation of the traditional model to the infiltration area is not applicable under the high sea condition any more, and the reduction of the model precision caused by wave influence under the high sea condition is not considered. In view of the above problems, there is a n