Numerical study of the effects of roughness of the inner wall of the pipe on the length of the pre-detonation

Today many research on the process of transition from Deflagration to Detonation Transition (DDT) has been found in many industries due to the explosive use in pulse detonation engines and in the meantime the roughness effect is remarkable In this research by choosing different roughness and studying its effect on the length of the predetonation it is tried to answer the question that what are the effects of roughness in the phenomenon of Deflagration to Detonation Transition To answer this question a numerical method was used In general it has been tried to simulate Deflagration to Detonation Transition numerically by using two Gambit and Fluent software in a closed tube with a smooth and five different rough surfaces and finally compare its results in six levels by plotting two velocitylocation diagrams and maximum kinetic energy of turbulence in the walllocation of this process The results show that the increase in pipe roughness reduced the time required for the occurrence of Deflagration to Detonation Transition and also reduced the length of predetonation In view of the maximum variation in the turbulence energy in the wall based on roughness it can be argued that increased roughness increases the turbulence of the flow which in turn increases the turbulent flame acceleration and facilitates the transition phenomenon