| Abstract: | The confine and heat are remarkable features in building fire research, as well as is a barrier for flow velocity profiles measurement, which the general method is unsuitable for this experimental environment. Therefore, this paper develops a measurement method for the acquisition of the thermal smoke flow velocity profiles in the fire building experiment. Firstly, we utilize the smoke itself particle distribution to replace the manual track particles in which reduce the complexity of the measurement method for fire experiments system. Secondly, we optimize the non-uniform distribution of smoke soot particle and utility the smoke stratification characteristics basing on the optical flow technology. The four optimized methods were compared to acquire reasonable smoke velocity distributions. Finally, we take advantage of filter post-process method to smooth the smoke velocity profiles in the main transportation direction. Moreover, a series of experiments and simulations show the feasibility of this image-based method in which the pre-process, optical calculation and smooth methods were established to denote reasonably the smoke flow velocity gradient and inclined upward trend nearby the corridor open. Meanwhile, it is not only in acquiring two-dimension smoke field velocity, while also can fulfill the other particle flow movement. |
