Experimental and numerical study on transient heat transfer for a twisted plate with different length in helium gas at various velocities

Figures & data

Figure 1. Test section.

Table 1. Experimental conditions.

Test fluid	Helium gas
Effective length	26.8 mm	67.8 mm	106.4 mm
Pitch number	1	3	5
Pitch size	20 mm
Period of heat generation rate	35 ms–14 s
Gas temperature	303 K
System pressure	500 kPa
Flow velocity	4–10 m/s
Reynolds number	2000–30,000

Figure 2. Time dependence of $\dot{Q}$, q and ΔT at 10 m/s.

Figure 3. Effect of length on heat transfer coefficient at various periods.

Figure 4. Effect of flow velocity on heat transfer coefficient at various periods.

Figure 5. Helical flow length for twisted plate.

Figure 6. Quasi-steady-state heat transfer at various swirl parameters.

Figure 7. Transient heat transfer for twisted plate at various flow velocities and periods.

Figure 8. Three-dimensional physical model.

Table 2. Calculating conditions.

Fluid	Helium gas
Pressure	500 kPa
Gas temperature (inlet)	303 K
Velocity	4–10 m/s
Period	0.14, 1.4, 14 s
Helical pitch	20 mm
Effective length	20, 60, 100 mm
Pitch numbers	1, 3, 5
Reynolds number	2000–30,000

Figure 9. Comparison of Q, q and ΔT with experimental data at various periods. (a) $\dot{Q}$, (b) q and (c) ΔT.

Figure 10. Comparison of simulation results with experimental data at various flow velocities.

Figure 11. Comparison of simulation results with experimental data for heat transfer coefficient at various effective lengths.

Figure 12. Distribution of heat transfer coefficient on the heater surface.

Figure 13. Cross section of temperature and velocity contours in YOZ plane.

Figure 14. 3D velocity distribution around the twisted plate.

Figure 15. Local heat transfer coefficient along the twisted plate.