DEVELOPMENT OF A LEAN STAGED COMBUSTOR FOR SMALL AERO-ENGINES

As the amount of air traffic is rapidly increasing, the local air quality around airports and the global climate change are two major concerns. Under the circumstances, the regulation for NOx emission becomes more stringent year after year. Lean burn technology is one of the key technologies for the next generation civil aircraft engines. Kawasaki Heavy Industries (KHI) has been developing a Lean Pre-mixed Pre-vaporized (LPP) combustor for around 10,000 lb thrust class engine under the project of Environmentally Compatible,Aircraft Engines for Small Aircraft (ECO)[1] led by New Energy and Industrial Technology Development Organization (NEDO) and Ministry of Economy, Trade and Industry (METI). In this paper the results of the LPP combustor development about reducing NOx emissions is presented. The LPP burner main premixed duct is designed to have better mixing fuel and air. KHI have achieved 30%CAEP4 NOx without deterioration of the other combustor performance. In general altitude relight would be one of the weak points for LPP combustion system. Successful lights were confirmed up to 30kft altitude condition in the multi sector rig, which is as good as that of the conventional combustors. Several LPP burners have been developed through CFD results. The burners have been spray-tested and combustion-tested in a single burner test rig in order to improve the burner potential. The burners selected in the single sector tests have been evaluated in a multi sector combustor rig with several combustor configurations. This paper describes the multi sector test results together with the brief introduction on burner development activities through burner tests.