供气管孔流量系数的实验和计算研究

一、单孔实验及分析由于供气管外气流速度较低 ,流过冲击孔的气流主要受管内气流轴向流动的影响。因此本实验仅研究管内有横向流动时单孔的流量系数和多孔管内轴向静压分布。图 1　单孔实验示意图单孔实验中 (图 1 )测量来流的总温T 、总压P 和静压Pd,并测量主管道流量 m和小孔出口气流静压Pj 和流量 mj。研究了孔径d与壁厚t之比t/d分别为 1 0 32、 0 75 4、 0 6 2 4三种不同的实验器。根据分析 ,选择无因次参数ΔP为变量 ,整理实验结果。ΔP =(P -Pj) /(P -Pd) ,为小孔气流速度头与主流速度头之比 ,它在一定程度上描述了主流对小…

RESEARCH ON DISCHARGE COEFFICIENT OF COOLING HOLES ON FEEDER TUBE

The main air flow supplied in the feeder tube is delivered to cooling holes with axis perpendicular to the main flow.This crossflow pattern exerts a significant influence on the hole discharge coefficient.The experimental investigation of the hole discharge coefficients and the measurement of static pressure distribution along the tube axis have been completed.It is shown that the discharge coefficient increases as the ratio of the orifice thickness to diameter and the velocity head ratio between orifice flow and tube flow increase.But the discharge coefficient approaches to a constant when the velocity head ratio is greater than 100.Empirical formulas have been dedueed from the experimental data.The static pressure distribution along the tube and the air flow rate allocation for the holes have been calculated by using the general air system computer program developed by author.The results ageree with the experimental data well.