Bath turbine team plans "world first"

Working with funding from the EPSRC and Siemens, engineers at the the facility are currently focusing their efforts on improving the design of gas turbine secondary air systems.

One of the most important cooling-air problems facing gas turbine designers today is the ingestion of hot mainstream gases into wheel spaces between the turbine discs and their adjacent casings. Rim seals are fitted at the periphery of the system, and a sealing flow of coolant is used to reduce or prevent ingress.

However, too much sealing air reduces the engine efficiency - with an associated increase in fuel consumption and CO2 emissions - and too little can cause serious overheating. This results in damage to the turbine rim, blade roots and disc, so getting the correct sealing balance is therefore of critical importance.

Previous research carried out at the University successfully modelled ingestion into a single-stage gas turbine. That research had great industry success in improving the design of gas turbine rim seals through extensive experimental measurements made on the stationary turbine disc and in the wheel-space between the discs.