Simulation Analysis Method Of Water Spray Of Aircraft Tyre

The splashing characteristics of large aircraft on the runway are an important project in airworthiness validation.At present,it is difficult to give quantitative results by using experimental methods and numerical simulation provides a possibility to study aircraft water spray in an efficient way.Based on the ESDU model and test results,this paper uses a Monte Carlo method to simulate the water spray,and the process of droplet breakage and secondary atomization is simplified.A numerical simulation software based on discrete droplet model is developed.In order to properly simulate the motion of the water spray in the flow field,the particle initial conditions and the flow conditions around the aircraft must be available.In this paper,the Monte Carlo simulation is employed to produce water particles and the initial states of the particles are given from the ESDU model.Then,the particle motion equation is solved by Runge-Kutta integration while the particle collision with surface of plane is applied at each step.In the algorithm for particle collision,an efficient detecting method for judging the collision between particles and aircraft surface grids is developed.In addition,in order to meet the requirement of water spray simulation,an efficient search algorithm is proposed to find the flow field data.In the process of programming,it is determined that the overall scheme of the program includes several modules such as data input,particle generation,motion equation solving,particle collision checking,flow field data search and result output.Two typical cases of tyre splashing of civil aircraft are numerically investigated by the method developed in this paper.Firstly,the water spray simulation is carried out under different running speed and different depth of water,and the quantitative results of water ingest by engine are obtained.Then in the case of the presence of side wind,the water splashing configuration are obtained.The quantitative results of water ingest by engine are obtained by typical wind velocity and different wind degree,which have certain engineering significance.