Determination of the Efficiency of a Cooled HP Turbine in a Compression Tube Facility

Abstract

The efficiency of a cooled transonic turbine stage was measured in a compression tube facility. The formulation takes into account mechanical losses, coolant flows and leakage flows. The proposed methodology allows computing the efficiency independently from the test rig. Owing to the short testing time (∼0.5 s), specific measurement and data reduction techniques are used. The paper details how the power, the overall mass flow, the mass-averaged inlet quantities and the stage pressure ratio are determined. The measurements of mechanical losses and of the thermodynamic properties of coolant and leakage flows are also described. Finally, results are presented and supported by an uncertainty analysis that identifies the random and systematic contributions to the final error.

Unsteady Strong Shock Interactions in a Transonic Turbine: Experimental and Numerical Analysis

“…The turbine efficiency is measured using the mechanical method as described by Dénos et al [32] and Yasa et al [33]. Based on a careful uncertainty analysis, one can quote for a single experiment a random error of about 0.4%, whereas the systematic or bias error is around 1.9% for a single experiment.…”

Accurate Turbine Inertia Measurement

“…This loss is a power law of the speed and function of density. The exact values of the equation were obtained from deceleration tests performed in the same turbine rotor between 6,500 and 5,000 RPM at different levels of pressure [1]:…”

“…Hence, the turbine mechanical torque is determined on the basis of rotor accelerations, t ¼ I Â a. The acceleration is monitored by a high-resolution tachometer, using a diode laser system ( [1,2]). Obviously, the inertia is a crucial parameter while determining the turbine efficiency uncertainty, 1% of error in the inertia results in 1% of error in the turbine power.…”

Novel 2D Transient Heat Conduction Calculation in a Cooled Rotor: Ventilation Preheating — Blowdown Flux

“…This loss is a power law of the speed and function of density. The exact values of the equation were obtained from deceleration tests performed in the same turbine rotor between 6500 RPM and 5000 RPM at different levels of pressure (Dénos et al[17].e. 0.3 kW at 6000 RPM.…”