| As one of the important parts of aero-engines,brush seals have many advantages such as low leakage,stable operation and flexibility.With the development of technical aeronautics and space in our country,the working conditions of brush seals have also become severe,which have promoted further research on the performance of brush seals.Tubes bank models are employed to study internal flow,heat transfer,and hysteresis of the brush seals in many researches.The methods and conclusions adopted in the macro-level tube bank model researches are not applicable to the micro-level gap between bristles.This paper studies influence of micro-level the tube bank models on internal flow and heat transfer of brush seals.The main contents of the present research are listed as follows:Firstly,Micro-Particle Image Velocimetry(Micro-PIV)were adopted to study the fluid flow inside a micro tube bank model at various inlet mass flow rates and various structural parameters.The mechanism of the internal flow of the micro tube bank model studied and the influence of structural parameters on flow field in micro tube bank model were investigated.Secondly based on the experimental conclusions,numerical simulations were conducted.Standard k-ε model with different wall functions was adopted to conduct numerical analysis.By analysis of experiments and numerical calculations,the velocity distribution along vertical gap line and the circumferential lines were pressented.Results show that the experimental results are similar to the results of standard k-εmodel with scalable wall functions.Finally,based on the conclusions from previous chapters,the three-dimensional tube bank model for fence height area of brush seal established.And this used standard k-ε with scalable wall functions to conduct numerical analysis.The research results show that the pressure drop appears in the bristle and gradually decreases from upstream to downstream.The velocity increases at the bristles gap and the jet flow appears at the last row of bristles. |
