Investigation of Injection Angle Influence on an Air/Fuel Premixer Performance Using Numerical Simulation

In the present article, the effect of injection angle of Methane gas into the air stream for an air/fuel premixer has been investigated by numerical simulations. The simulations have been done for injection angles from 90° or cross flow situation to 180°(counter flow) by the use of ANSYS Fluent software. Mixture uniformity was determined in terms of uniformity index of CH4 mass fraction at different outlet cross sections. Results have shown that firstly, mixture uniformity was increased with increase in injection angle which means approaching counter flow situation; after 165° angle this trend was inverted but in counter flow situation the uniformity increased once more. Moreover, it was shown that injection angle effectiveness depends on airflow Reynolds number and increases with an increase in Reynolds number. In addition, the dependence of premixer performance on Reynolds number at first decreases with increase in injection angle but rises again after 165° angle.