Numerical study of the reverse shock wave-outlet nozzle

Secondary wave system in order to study the impact of the pressure exchange refrigerator isentropic refrigeration efficiency, eliminate secondary wave system outlet nozzle structure, called the wave-partition thickness of 1mm spacer pitch 3mm. By the number of executed piece spacer pitch adjustment, each executed piece 0.5mm. All bulkhead by two bolted as a whole, framed and put in the outlet nozzle. Macroscopically, the separator can be blocked within the outlet nozzle channel in the pre-discharged high-temperature and high-pressure gas mixed in the latter part of the exhaust gas infiltration, thereby reducing the compression of gas within the outlet nozzle of the post-exhaust phase reverse of the gas within the channels. Micro level, the root cause of the reverse shock of right line expansion wave in the reflection of the open end of the outlet nozzle. Channel airflow in the outlet nozzle exhaust pre-left line the role of the expansion wave, high speed, static pressure is lower than the outlet nozzle hydrostatic late into the exhaust channel, to form a reverse compression wave. If the closed port, higher airflow channel right speed, in the solid wall end of the accumulation of the same formation of the reverse shock. Therefore closed ports, and can not eliminate the reverse shock. The use of partially open, partially closed structure of the outlet nozzle, can ensure that the airflow outflow channel arbitrary moment. Channel airflow is blocked by the separator to form a left-compression wave, and asked to partition the role of low-pressure air to form a left-expansion wave. Left-compression wave with the left line expansion waves cancel each other out, so that we can greatly weakened the formation of the reverse shock wave reflection compression wave superposition, to eliminate the reverse shock within the purpose of the channel. Separator Q generation of low-pressure air and the structural dimensions are closely related. Experimental machine channel solid wall thickness 2.5mm, wave absorption is partition J, J pitch 3mm, so the wave rotor rotation, the formation of the partition flow airflow periodic intervals. Channel solid wall corresponding to the flow channel, in the area of ??low pressure formed under the action of the expansion wave. Plus a two-dimensional wave-machine cycle simulation compared with the wave-only outlet nozzle structure of the model are subject to change. Choice of mathematical models and numerical methods are the same, the same set of boundary conditions. From the figure can be seen: the outlet nozzle is added to the wave-channel, there is no obvious secondary wave system generated reverse shock eliminate. Incident wave stage phase channel and the low-temperature exhaust flow field and wave-consistent. The channel internal cycle gas still in the formation of a high temperature zone.