New twist on turbines

In-Depth

Engineers at the Southwest Research Institute have developed and built a radial flow gas turbine that is very rugged, low-cost and easy to repair.

Engineers at the Southwest Research Institute (SwRI) in the US have developed and built a radial flow gas turbine that is very rugged, low-cost and easy to repair.

Many of the approximately 50,000 modern industrial gas turbines in use throughout the world are technically complex machines that have multiple rotating parts, lubricating oil systems and sophisticated electronic controls. Some are so technically sophisticated that many users cannot perform basic repairs and maintenance.

Most gas turbines use an axial flow compressor and an axial flow turbine design, and have more than a thousand individual parts.

In contrast, the SwRI design is based on a purely radial flow, open-cycle gas turbine concept, consisting of three principal components: a centrifugal compressor, a radial flow combustor and a high-impulse radial turbine. The compressor and turbine are mounted on a single rotating disk while the combustor and turbine nozzles are mounted on an opposing stationary disk.

"The fundamental difference between the SwRI centrifugal gas turbine and conventional gas turbines is that the compressor and turbine section are installed on the same side of the rotating wheel, while the combustor and nozzle are mounted on the stationary shroud. This is the most basic arrangement possible and allows the design to be extremely rugged, simple and inexpensive to manufacture," said Dr. Klaus Brun, a principal engineer in SwRI's Mechanical and Materials Engineering Division and developer of the innovative design.

Stator and rotor disks

"The entire gas turbine assembly consists of only two relatively easy-to-manufacture components. Because there is only one rotating part, costs of manufacture, maintenance, repair and replacement are low."

The SwRI gas turbine is compact, light and portable, making it an ideal candidate for a variety of applications including military battlefield, oil product flare gas and on-ship auxiliary power unit generation. Other applications include nanotechnology gas turbines, distributed power generation, combined heat and power, and hydrogen power generation.

A patent is pending on the new design.