The Design and Performance of a High Work Research Turbine

Abstract

This paper describes the design and performance of a high work single-stage research turbine with a pressure ratio of 5.0, a stage loading of 2.2, and cooled stator and rotor. Tests were carried out in a cold flow rig and as part of a gas generator facility. The performance of the turbine was assessed, through measurements of reaction, rotor exit conditions and efficiency, with and without airfoil cooling. The measured cooled efficiency in the cold rig was 79.9 percent, which, after correcting for temperature and measuring plane location, matched reasonably well the efficiency of 81.5 percent in the gas generator test. The effect of cooling, as measured in the cold rig, was to reduce the turbine efficiency by 2.1 percent. A part-load turbine map was obtained at 100, 110, and 118 percent design speed and at 3.9, 5.0, and 6.0 pressure ratio. The influence of speed and the limit load pattern for transonic turbines are discussed. The effect of the downstream measuring distance on the calculated efficiency was determined using three different locations. An efficiency drop of 3.2 percent was measured between the rotor trailing edge plane and a distance four chords downstream.

Performance analysis of a transonic high-pressure turbine

“…Moustapha et al [7] (Highly Loaded Turbine) showed the effect of blade loading on high loaded ( H /U 2 = 2.4) stage efficiency at off-design conditions; increase in the rotor blade loading by 53 per cent reduced the efficiency by 2.5 per cent. Vlasic et al [8] (High Work Research Turbine) investigated a single-stage turbine with a pressure ratio of 5 and stage loading of 2.2, the efficiency is reduced by 2.1 per cent when the turbine-cooling rate goes from 0 to 11 per cent. Woinowsky-Krieger et al [9] showed that a 10 per cent reduction in the rotational speed resulted in a decrease of 3 per cent in the efficiency for a single-stage transonic turbine.…”

Investigation of the flowfield on a vaneless counter-rotating turbine with seal cavity flow ejection

“…At the same time, a number of other investigations considered the influence of blade cooling on shock wave loss. Bohn et al, 19 Vlasic et al 20 investigated losses downstream of transonic airfoils with trailing edge ejection. They found that the pressure at base region arises because of trailing edge ejection.…”

“…Bohn et al., 19 Vlasic et al. 20 investigated losses downstream of transonic airfoils with trailing edge ejection. They found that the pressure at base region arises because of trailing edge ejection.…”