Numerical Analysis of Effect of Boundary Layer Characteristics on the Flow Field in S-shaped Inlet

Jia Ren,Qiyang Hu,Mingzhen Li,He Liu,Naiming Wu,J.W Gu,X.L Chen,E.H Liu

doi:10.1051/matecconf/20152501011

Abstract

In order to explore the effect of boundary layer thickness and pressure gradient on the perfor- mance of the flow field in the inlet, we design a high offset rate S-shaped inlet based on a certain unmanned aeri- al vehicle (UAV), and its author has analyzed the effect of boundary layer characteristics on the inlet with nu- merical simulation method. The suction of boundary layer which leads to separation zone not only becomes longer in the inlet, but also moves to the center plane of symmetry, the separation point of boundary layer ap- pears in advance as pressure gradient increases. Considering the influence of the boundary layer, various perfor- mance parameters all exceeds that of the uniform entrance inlet conditions, especially the circumferential total pressure distortion of outlet increased by 58.2% at most, obviously can't meet the engine to work properly, so we must consider and pay attention to the effect of the boundary layer characteristics on the flow field in the S-shaped inlet.

Highlights

The engine inlet is an important component of the propulsion system; its performance quality directly affects the performance of the engine
Wang Xiao [15] studied the three dimensional viscous flow field numerical simulation based on five specific short S inlets using CFX software, the results show that even increase the length of the straight segment, such S-inlet is difficult to delay flow separation
The purpose of this paper is to study the influence of inlet boundary layer on the characteristic of S flow field using the method of numerical simulation

Summary

Introduction

The engine inlet is an important component of the propulsion system; its performance quality directly affects the performance of the engine. Flowing air flow in the S-shaped pipe has adverse pressure gradient due to the particularity of its shape, and the inlet air flow is very difficult to stick attached to the bending of the pipe wall, so prone to [1] separation. Airframe boundary layer can cause the inlet total pressure recovery coefficient decreased when the plane flights, it will cause the total pressure distortion and instability of airflow. Wang Xiao [15] studied the three dimensional viscous flow field numerical simulation based on five specific short S inlets using CFX software, the results show that even increase the length of the straight segment, such S-inlet is difficult to delay flow separation. The current research on characteristic of S flow field in the inlet boundary layer is not enough

Objectives

Results

Conclusion