Book Description

An investigation has been made of the effect on the performance of a radial-flow exhaust-gas turbosupercharger turbine with a 12.75-inch tip diameter of various inlet pressures, inlet temperatures, wheel speeds, pressure ratios, and cooling-air flows. For a given blade-to-jet speed ratio, variation in pressure ratio from 1.5 to 4.0 and inlet temperature from 800 to 1200 degrees R had only a small effect on turbine efficiency. For blade-to-jet speed ratios of 0.5 to 0.6, the efficiency increased 4.5 points as inlet pressure increased from 20 to 50 inches of mercury absolute. Cooling-air flow had no measurable effect on turbine efficiency within the accuracy of the tests in the test range: namely, ratios of cooling-air flow to turbine gas flow from 0 to 14 percent, turbine pressure ratio of 2.0, turbine inlet total pressures from 15 to 40 inches of mercury absolute, and inlet temperatures from 800 to 2000 degrees R.