Dr. Akihiro Hayakawa is an associate professor at the Institute of Fluid Science, Tohoku University, Japan. He received his PhD at Kyushu University, Japan, in 2013. His research interests are ammonia combustion, turbulent combustion, high pressure combustion, and laser diagnostics, such as LITGS (Laser Induced Thermal Grating Spectroscopy). Dr. Hayakawa is working at IFS from April 2013 as assistant professor in Prof. Hideaki Kobayashi’s laboratory. He was promoted to an associate professor in 2020. He was a visiting researcher of Prof. Simone Hochgreb’s laboratory at University of Cambridge in 2015.

Abstract

Laminar flame characteristics of ammonia: burning velocity and product gas

In this presentation, I will introduce our results of premixed laminar flame characteristics, such as laminar burning velocity and product gas, of ammonia/air premixed flames. Laminar burning velocity is measured through the observation of spherically propagating flames in a high pressure constant volume combustion chamber. We measured the premixed laminar flames up to 0.5 MPa and 500 K, and the effects of pressure and mixture temperature on laminar burning velocity were clarified. Product gas characteristics were also important as NOx and unburnt ammonia may be produced from ammonia flames to achieve an appropriate combustion procedure to achieve minimum emissions of these species. Because of weak flame characteristics of ammonia, it was difficult to stabilized and sample the product gas from premixed laminar ammonia/air flames. In order to stabilize ammonia/air flames, stagnation flame configuration was adopted in this study. The stagnation plate has a sampling hole, and product gas could be sampled from ammonia/air premixed flames. Important products from ammonia flames, such as NO and unburnt NH3, were detected for various equivalence ratio cases.