Abstract
Forced convection transient heat transfer for helium gas flowing over a twisted plate with different length was experimentally and theoretically studied. The heat generation rate of the twisted plate was increased with a function of Q=Q_0 exp(t/τ) (where t is time, τ is period). Experiment was carried out for three kinds of effective length of 26.8, 67.8 and 106.4 mm at various periods ranged from 35 ms to 13 s and at gas temperature of 303 K under 500 kPa. The flow velocities ranged from 4 m/s to 10 m/s. It was found that average heat transfer coefficient becomes higher with the increase of flow velocity and decreases with the increase of plate length under the same period of heat generation rate. Numerical simulation results were obtained for average surface temperature difference, heat flux and average heat transfer coefficient of twisted plate and showed reasonable agreement with experimental data.