The thermo-acoustic engine is a device that operates on the temperature difference created across the regenerator mesh through hot and cold heat exchangers which produce the oscillations. Computation fluid dynamics modelling techniques have used to discuss the issues of characterising and quantifying heat transfer in the thermo-acoustic engine prototype. Using the unsteady Navier–Stokes equation, the paper investigated the distribution of pressure, velocity and temperature inside the engine assembly. The k–ϵ model for the thermo-acoustic engine has considered for energy and wall Prandtl numbers, to consider the effect of buoyancy on the turbulence generation. For analysis, the wall Prandtl number has considered as 0.85. The six monitoring points have selected on the engine assembly to observe the generation and transmission of the acoustic waves. The computation results have shown an amplification acoustic power inside the thermo-acoustic engine loop. The nonlinear phenomena have also visualised in the analysis of the thermo-acoustic engine.