A Novel Design of Cooling Air Supply System with Dual Row Pre-Swirl Nozzles

A novel design of cooling air supply system with dual row pre-swirl nozzles (DRPM) is promoted and investigated. Simplified theoretical analysis and numerical simulation are used to estimate the total temperature reduction and mass flow rate characteristic of DRPM and compared with single row pre-swirl nozzle model (SRPM). The results show that, both models have similar flow structure and the variation of total temperature reduction and dimensionless mass flow rate with rotational Reynolds number and pressure ratio is also similar. Which have an inflection point with the increase of rotational Reynolds number but increases monotonically with the variation of pressure ratio. The pre-swirl system has the maximum flow rate and temperature reduction when the inflow Angle equal to 0 or the swirl ratio equal to 1 at the inlet of the receiver hole. The increase in pressure ratio improves the total temperature reduction and dimensionless mass flow rate as well. In the range of rotational Reynolds number calculated, DRPM can increase the dimensionless mass flow rate by 3.0% but the total temperature reduction decreased by 37.8% in average compared with SRPM. On the other hand, the dimensionless mass flow rate increased by 2.8% and total temperature reduction decreased by 14.9% in average in the range of pressure ratio calculated. Numerical results are in good agreement with the results calculated by simplified theoretical formulas.