Pressure Loss Characteristics in Rotating Coolant Passages of Gas Turbine

Pressue loss characteristics of flow in rotating coolant passages of gas turbine intermediate shaft were studied experimentally. The effects of rotational Reynolds number and coolant flow rate on the pressure loss characteristics of flow in the coolant passages were investigated by using a rotatinal test facility with disks having diameter of 0.5m and maximum rotational speed of 4800 rpm. A multi-points pressure measurement system with a rotary connector was employed to measure both the wall static pressure along the passages and the total pressure in the intermediate shaft. The results led to an understanding that the strength of the swirl flow controls the total pressure distribution in the central portion of the shaft. On the other hand, there occurreed a large pressure loss at both the junction and in the region of branching of coolant passages.