59164 - Numerical Investigation on the Flow Characteristics in a Cover-Plate Pre-Swirl System 

This paper presents a numerical investigation on the flow characteristics in a cover-plate pre-swirl system. The Reynolds-averaged Navier-Stokes equations, coupled with the standard k-ε turbulent model, are adopted and solved. With the inlet total pressure and total temperature being constant, the influences of the temperature reduction and flow resistance by changing pressure ratio and rotational Reynolds numbers were conducted. Flow features in the pre-swirl nozzle, rotor-stator cavity, receiver hole and rotating cavity were summarized. The results obtained in this study indicate that, as the air accelerated by the pre-swirl nozzle, the difference of circumferential velocity between the air and the rotational domain would be reduced, and the static temperature of the air will be decreased. The pressure drop in the pre-swirl system mainly occurs in the pre-swirl nozzle and the rotor-stator cavity. In addition, with the increase of rotating Reynolds numbers, the proportion of the pressure drop in the pre-swirl nozzle will increase. Moreover, with the increase of the pressure ratio, the air mass flow rate and the circumferential velocity of the air out of the nozzle increased, thereby leading to an increment in temperature reduction. The temperature reduction of the pre-swirl system will first increase to a maximum and then decrease with the increasing of the rotational Reynolds number.