Flow Field Analysis Of Aircraft Deicing Vehicle Engine Exhaust System

Aircraft deicing vehicle is one of the airport's equipment for deicing in winter. When deicing vehicle works, it will run around the aircraft in a low speed. Its working environment requires deicing vehicle's engine of good performance. The engine exhaust system of the car is one of the most important parts of the vehicle, not only because of its role in reducing waste gas and noise, but also its direct influences on the engine in terms of the exhaust function, economic interest, and power performance. Therefore, further study on exhaust system of the deicing vehicle is very necessary. The flow in exhaust system is the complex 3D unsteady flow, so the study on its theory can only be done in a simplified and abstract way with no accurate analytical simulation. In addition, the traditional research method requires many personnel and time inputs. This essay, therefore, select CFD to study and analyze the internal flow of the exhaust system of the deicing car, which plays an important role in both the designing and optimizing of the exhaust system.This research, in cooperation with the project "Flow field analysis of aircraft deicing vehicle engine exhaust system", analyze and calculate theoretically the concerning contents of deicing vehicle engine exhaust system first based on the fluid dynamics' theory and CFD's principles. Simulation analysis is also carried out in the following aspects. Firstly, using GT-Power software to create 1D model of airplane deicing vehicle's engine. Comparing the results of simulation and the actual external characteristics data to check the model is correct or not. Secondly, creating the 1D model of the exhaust system so as to study the influences of the exhaust system in different structures on the engine and find out the best structure of exhaust system for certain engine. Thirdly, creating 3D model for the previous system and the two optimized systems. Based on the Fluent software, analyzing and calculating the internal flow of the three exhaust systems to make clear the pressure, temperature, speed and other figures of the internal flow of exhaust systems. The exhaust back pressure and pressure drop as the mainly reference factors, the floe speed of the internal flow and the temperature the subordinate reference factors, finding out the best structure of the exhaust system. Finally, check the feasibility of this research on the exhaust system of the deicing vehicle through engine testing.Through theoretical and numerical simulation analysis of engine exhaust system of aircraft deicing vehicle, here comes the conclusion that in 1D simulation, when the pipe cross-section diameter of exhaust system is 80 mm, the engine has maximum torque and power, but minimum fuel consumption;In 3D simulation, exhaust system containing tapered pipe structure which generates lower back pressure and pressure drop can exhaust gas more quickly.