Numerical simulation on enhanced heat transfer performance of a new multi-channel twisted tape
Numerical simulations were used to investigate the flow heat transfer characteristics of heat exchanger tubes with multi-channel twisted tapes interpolated with alternating clockwise and counterclockwise(C-CC)twisting directions at the Re=6 000-12 000.The results show that the Nu of heat exchanger tubes with C-CC type multi-channel twisted tapes is positively related to the number of channels(N)and Re and negatively related to the twist ratio(TR),with a maximum increase of 30.7%relative to the classical twisted tape(N=2).The coefficient of friction is positively correlated with N and negatively with Re and TR,with a maximum increase of 304%relative to the classical twisted tape.The comprehensive heat transfer factor is negatively correlated with Re and N,increasing first and then decreasing with the increase in TR,with a maximum of 0.887.At smaller TR,the C-CC type multi-channel twisted tape has better enhanced heat transfer performance than conventional multi-channel twisted tape.