By keeping its geometry simple, engineers at the Southwest Research Institute have developed a low cost radial flow gas turbine that uses only two main components and one rotating element, according to Dr. Klaus Brun, principal engineer in SwRI's Mechanical and Materials Engineering division. The turbine is softly targeted for military applications, he says, especially those in dusty, sandy areas where ingested air can quickly ruin running gear. It may also interest oil and gas companies looking for inexpensive ways to recover energy from gas now being flared, he says.
Rather than the standard in line arrangement of axial compressor and axial turbine, the new design mounts a compressor and turbine concentrically on a common rotating disc. The centrifugal compressor sits inboard where it's ringed by a stationary radial flow combustor and nozzles and the high impulse radial turbine itself.
Says Brun, the whole assembly is composed of two easily-made components, compared to the many parts that go into a conventional gas turbine. The idea was to develop a unit that could be affordably spared, he says. Also, the design itself is less susceptible to wear from ingested grit, suiting it to a desert climate.
The institute has just begun prototype testing and expects to have a demonstration unit ready around the end of the year. The design will be a 50 kW version, with stress being the limiting factor on sizes beyond half a megawatt, Brun says. An 8 kW version is planned as a generating source for cathodic pipeline protection. Even smaller units will be able to furnish personal power, and the design could carry over to the nano realm, he says.
The design was developed with the institute's internal research funds. A patent is pending.