Mesoscopic model derivation and numerical simulation of heat flow around wet string grid wire
It is significant to control the tunnel construction environment to purify and cool the air.To find the general law of heat transfer of hot fluid flowing through wet string grid wire,the lattice Boltzmann method was used to establish a mesoscopic model of heat transfer around a cylinder at a low Reynolds number,and the accuracy of the model was further verified by combining the existing correlation formula.Based on the above model,the flow field and temperature field distribution around a series cylinder with Re=200 was investigated.The flow field and temperature field structure evolution with different spacing ratios L/D was quantified.The relationship between the heat transfer characteristic parameter Nu and spacing ratio and heat transfer time was analyzed to reveal the influence of flow field structure on the flow field structure of the temperature field.The results show that:the distribution law of the flow and temperature fields is consistent,and different L/D flow fields and temperature fields show different characteristics.When the L/D value is small,a dead flow zone is formed between the upstream and downstream cylinders,resulting in a poor heat transfer effect.With increasing L/D value,the downstream cylinder's inhibition effect on the upstream cylinder's flow field is weakened,vortices appear in the wake,the dead flow zone is broken,and the mixing of hot and cold fluids is enhanced.There is a critical spacing ratio of L/D=2.65;beyond this critical spacing,the average Nu of the downstream cylinder is always greater than that of the upstream cylinder.When L/D=4,the average Nu of the upstream cylinder tends to be stable.In practical engineering applications,the spacing ratio L/D≥4.
safety and hygiene engineering technologywet string gridheat transfer around a cylindermesoscopic modeltemperature fieldspacing ratio
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