精密水槽收缩段流场模拟与收缩曲线选型评估

通过求解RANS方程,数值模拟了精密水槽收缩段的流场特性。针对两种不同出口尺寸不同收缩比的收缩段,选取了三种不同的收缩曲线来进行选型评估。根据壁面是否分离、逆压梯度变化缓和程度、出口速度均匀度,来判断不同收缩曲线的优劣。研究表明:对于出口尺寸为250 mm×20 mm、收缩比为30的收缩段,双三次收缩曲线是最优的;对于出口尺寸为250 mm×10 mm、收缩比为60的收缩段,维氏收缩曲线是最优的。本次数值模拟计算的工作可为精密水槽收缩段优化设计工作提供借鉴。

Numerical Simulation on the Flow Field in Contraction Section of Precision Water Flume and Evaluation About the Contraction Curves

The on-site calibration of antennas is getting much more attention now because it can greatly impact the performance of the phased array radar. This paper introduces the current situation of on-site calibration of antennas and puts forward some existent problems. It focuses on analysing the advantages of optical-electromagnetic field detect technique and proving on-site calibration of phased array radar antennas based on optical technology is entirely feasible, by building the on-site calibration device and doing some experiments. This technology can calibrate parameters of phased array radar antennas accurately and have less impact on radiation field of antennas. It can meet the requirements of the on-site calibration of phased array radar antennas.