Modification design of inlet duct for a helium circulator

A three dimensional steady turbulence numerical simulation technique was applied to simulate the internal flow of the inlet duct. A shear-stress transport k-ω turbulent model based on Reynolds averaged Navier-Stokes equations was used. Based on the simulation results, the origins for the internal flow losses were analyzed, and then a series of modification designs on the geometry of the inlet duct were carried out. The results showed that the flow losses in the inlet duct were mainly caused by the flow separation and vortex flow. After the modification, a best result of 56.3% loss decrease is achieved, which meets the engineering requirement. (authors)