CHENNAI: Indian Institute of Technology, Madras, researchers have developed a software to predict pressure oscillation as well as its amplitude or strength in advance to adopt measures to control them. The software, which works on data acquired during stable operating conditions of combustors, has been tested and commercialised.
Induja Pavithran, interdisciplinary PhD student and one of the researchers, said these oscillations in the pressure, which are often self-sustained, can be even 100% more than the mean pressure. They can be strong enough to cause violent vibrations and damage engines, electronics and navigation components.
“We call this oscillation as thermoacoustic instability. What we have done is to predict this instability well in advance- when it is going to happen and how strong it is going to be- without operating in those conditions. With all our findings and data, we have made a standalone application, which has been commercialised,” she said.
The researchers said their software application could save gas turbine manufacturers billions of rupees as they operate engines in lean conditions more air and less fuel that is more susceptible to oscillation.
With the software, Professor R I Sujith, D Srinivasan Chair Professor, department of Aerospace Engineering said, “Manufacturers of industrial gas turbines can use this method to estimate the amplitude, even without approaching anywhere close to thermoacoustic instability. The prediction can be made well in advance without exposing the combustor to large amplitudes and endangering it.”
The researchers said it was such combustion instabilities in the F-1 rocket engine that initially hindered Nasa’s Apollo program and the engineers made changes in the design or fuel path on a trial and error basis. “Recently there has been a lot of research to solve this problem of oscillation. One is the early warning or prediction. The other is passive control measures like slight change in the design,” the researchers said.