Numerical investigation into the pressure loss and air distribution uniformity of a hydrogen-rich Micromix combustor

The large number of nozzles in the Micromix combustor would increase flow resistance and make air uniform distribution difficult. It was found that the Micromix combustor was divided into transition region and multiple premixing-channel region. In transition region, the inlet relative velocity and transition-region relative velocity were the main factors. In premixing-channel region, the increase of premixing-channel density would reduce the pressure loss, but it had the opposite effect on air distribution. The total pressure loss was fitted by the characteristic parameters, and the correlation coefficient can reach 0.98. The air distribution uniformity was calculated by the self-compiled post-processing program, and it was linear according to the premixing-channel density. Further, the diverging structure at transition region can reduce the pressure loss to blow 3%, and keep the air distribution uniformity above 0.9. Moreover, the local structure optimization of center and edge-climax nozzles can further increase the air distribution uniformity above 0.95.