On energy dissipation spectra in turbulent non-premixed jets with local extinction

The turbulent kinetic energy (TKE) and its dissipation spectra are analyzed using a DNS database of temporally evolving non-premixed jet flame experiencing high level of local extinction. It is found out that when scaled using Favre averaged turbulent dissipation rate (̃) and the cutoff scale () corresponding to the Batchelor scale, both TKE and its dissipation spectra collapse well in different planes across the flame in both low-medium and high wave number dissipative ranges. Further, the spectra are compared with the model spectra, it is found that again using the previous scaling laws the agreement is better than the classical scaling laws for spectra involving Kolmogorov scale, especially in high wave number regions.