马赫数连续可变跨声速湿蒸汽风洞的研制

用于跨声速气动测量的探针须从亚声速到超声速范围进行标定。变质量槽式喷管通过扩张段壁面上槽缝流出部分气流的自适应特性可在不同背压下得到不同出口马赫数，从而使标定气动探针的风洞实现马赫数从0到超声速的连续变化。为了研究采用湿蒸汽为工质的变质量槽式喷管的性能及优化其结构，采用三维犖-犛方程以及可实现犽-ε湍流模型对其进行了详细的数值仿真。结果表明收缩段型线、扩张段长度及壁槽尺寸等对喷管流场特性有重要影响，喷管进出口压比在一定范围内，槽式喷管有最优的收缩段型线、扩张段长度和开槽尺寸。根据数值仿真结果研制了马赫数从0到1．6连续可变的跨声速湿蒸汽风洞，对此风洞性能进行验证，表明该风洞在马赫数从零到超声速范围内可获得均匀、稳定的出口气流，满足跨声速湿蒸汽气动探针的标定要求。

The development of a transonic wet steam wind tunnel with tunable Mach number

The probe used for transonic flow measurement should be calibrated in a wind tunnel with Mach number from subsonic to transonic.The Mach number at the outlet of the slotted nozzle is changeable due to the self-adaptive effect of the nozzle in different backpressure.Therefore,the wind tunnel equipped with the slotted nozzle may be operated from subsonic to ultrason-ic for calibrating the transonic probe.For studying the performance of the slotted nozzle with wet steam as the working medium and optimizing its structure,detail numerical simulation is carried out by solving 3-D N-S equations and the realizablek-εturbulence model.The numerical results show that converging curve、divergent section length and slot size may affect flow field characteristic of the nozzle seriously.In a certain range of backpressure and inlet pressure ratio,there are optimal convergent curve,divergent length and slot size.According to the results of the numerical simulation,a wind tunnel equipped with the slotted nozzle is developed.The Mach number of the tunnel with wet steam as the working medium may be continuously varied from zero to 1 .6 . The experimental results show that the flow at the outlet of the nozzle with such optimal structure are uniform and stable in a wide range of Mach number from zero to supersonic.It is qualified to meet the requirements of transonic probe calibrating.