Jet flame in modes of manageable instability development inside the source of jet formation is one of the methods for controlling the space-time and thermodynamic parameters of the torch. When a system of vortices flows into a free atmosphere, their interaction with the mixing layer and the flame front is accompanied by the appearance of a number of effects. The introduction of artificial perturbations into the flow allowed initiating the onset of a laminarturbulent transition in the tube, which led to the formation of vortex structures in the jet stream. Hot-wire anemometric measurements of the velocity pulsations in the isothermal flow has shown that the disturbance introduced by the controlled valve is an acoustic precursor and a large-scale vortex formation. In this work, we investigated the effect of a system of turbulent spots on a laminar diffusion plume. Based on the two-point space-time temperature correlation dependences, data characterizing the rate of propagation of thermal perturbations during burning of H2/CO2 and C3H8/CO2 fuel mixtures were obtained.