Experimental and numerical studies on a trapped vortex combustor with different struts width

• An novel aerodynamic multi-point fueling (AMF) setup is designed for trapped vortex combustor main fueling.
• Effect of strut width on combustion and pollutant emissions is evaluated experimentally and numerically.
• Wider struts protect the tail combusting flow of struts and bluff body from being quenched by mainstream.
• Slenderer struts enhance mixing cavity flow and mainstream, and thus reduce NOx emission.

To investigate the effect of strut width on combustion efficiency and pollutant emissions, a trapped vortex combustor with interchangeable aerodynamic multi-point fueling (AMF) setups is designed. Exhaust gas composition is measured at the exit of the combustor. Results show that lacking of protection of slenderer struts leads that the flame coming from cavity is prone to be quenched; thus combustion efficiency for cavity-only fueling conditions is relative lower. Thus, CO and HC emissions are relative higher. However, as main fueling is available, the corresponding overall combustion efficiencies become higher especially for Ma = 0.3. This can be attributed to larger number of struts and thus larger wet perimeter of mainstream passages. Additionally, activating of main fueling is helpful for decreasing CO and HC and thus elevating combustion efficiency. Numerical simulations of non-reacting and reacting flow are also accomplished. Although the numerical simulation results exhibit flow structure discrepancy between non-reacting and reacting simulations, the conclusion about protection of wider struts and mixing enhancement of slenderer struts are accordant.