Abstract: A transient thermal liquid crystal experiment and the numerical simulation were conducted on the three-channel swirling cooling structure inside the turbine blade. The results were compared with those of the ordinary turning channel at when Reynolds number is 40000. By conducting the transient experiment, high precision distribution of Nusselt numbers and the pressure loss along the channel were obtained. Combined with the numerical calculation results, the following conclusions were drawn: the swirl channel significantly enhanced the heat transfer capacity and the heat transfer uniformity of the system. Compared with the ordinary turning channel, the average Nusselt numbers on the wall of the second and third processes were increased by 60% and 57%, respectively. The impact loss and the throttling loss at the turning position were the main pressure losses of the three-channel structure. The pressure coefficient of the whole system of the swirl channel was about three times that of the ordinary turning channel, and it increased with Reynolds number. Numerical calculation indicated that the total pressure loss in the swirl channel was reduced by 25% compared with the static pressure loss. It was more scientific and reasonable to use the total pressure to analyze the pressure coefficient along the channel.

Key words: swirl cooling; thermal liquid crystal; heat transfer; pressure coefficient