Experimental And Numerical Study Of Flow Characteristic On Air Bleeding Manifold

Air bleeding manifold is an important component in the active clearance control system.The internal flow characteristic of the air bleeding manifold will have significant influence on engine.The study of the internal characteristic and the loss mechanism provides theoretical basis for optimal design.This paper studied the internal flow characteristic and the impact of the inlet Mach under typical working condition by using experimental measurement method and numerical simulation.First of all,this paper select air bleeding manifold as experimental subject,establish the experimental measurement scheme,and perform the flow characteristics experiments to obtain the total pressure recovery coefficient and other flow characteristics.Results indicate that the flow losses are small under low Mach number with the total pressure recovery coefficient of around 0.99.With the increase of Mach number and the flow of air bleeding,the total pressure recovery decreases.The radial distributions of outlet total pressure are uniform under low Mach number and tend to be less uniform with the increase of Mach number.After the above work,the measured results and numerical simulation results are compared.The test measured flow characteristic curve has a good agreement with the results of numerical simulation.With the increase of Mach number and the flow of air bleeding,the error range of the total pressure recovery coefficient increases.Finally,the analysis of internal flow characteristic and the loss mechanism by using numerical simulation shows that the flow separation occurs at the upside and downside near the first bend,which also induces the vortex pair and causes the non-uniformity of the flow field at the outlet.In addition,the profile of air bleeding manifold and the cross-section area have greatly influence on the flow structure,and the strong deflection of the first bend at downside surface is the main factor causing the flow separation.