Heat Transfer In Swirl Flow Research Articles

A numerical model for swirl flow cooling in high-heat-flux particle beam targets and the design of a swirl-flow-based plasma limiter

An unsteady, two-dimensional heat conduction code has been used to study the performance of swirl-flow-based neutral particle beam targets. The model includes the effects of two-phase heat transfer and asymmetric heating of tubular elements. The calorimeter installed in the Medium Energy Test Facility, which has been subjected to 30-s neutral beam pulses with incident heat flux intensities of ⩾ 5 kW/cm 2 , has been modeled. The numerical results indicate that local heat fluxes in excess of 7 kW/cm 2 occur at the water-cooled surface on the side exposed to the beam. This exceeds critical heat flux limits for uniformly heated tubes with straight flow by approximately a factor of 5. The design of a plasma limiter based on swirl flow heat transfer is presented.

Closure to “Discussion of ‘Heat Transfer and Pressure Drop in Tape-Generated Swirl Flow of Single-Phase Water’” (1969, ASME J. Heat Transfer, 91, p. 442)

Closure to “Discussion of ‘Heat Transfer and Pressure Drop in Tape-Generated Swirl Flow of Single-Phase Water’” (1969, ASME J. Heat Transfer, 91, p. 442)

Heat Transfer and Pressure Drop in Tape-Generated Swirl Flow of Single-Phase Water

This paper summarizes the results of an investigation of the heat-transfer and pressure drop characteristics of single-phase water in tape-generated swirl flow. Extensive data are reported for electrically heated or water-cooled tubular test sections with tight fitting, full length tapes with twist ratios from 2.5 to 9.2. A method was developed for predicting the heat-transfer coefficient for swirl flow based upon the premise that the observed improvement is due primarily to: (a) the increased flow path created by the tape, (b) the increased circulation created with heating due to the large centrifugal force, and (c) the tape fin effect. The experimental results of this and previous swirl flow investigations are in good agreement with the prediction method. Correlations are also presented for adiabatic and diabatic friction factors. Heat-transfer and friction data are combined in a constant pumping power comparison for swirl and straight flow, which indicates that improvements of 20 percent can readily be obtained with swirl flow.

Discussion: “Heat Transfer and Pressure Drop in Tape-Generated Swirl Flow of Single-Phase Water” (Lopina, R. F., and Bergles, A. E., 1969, ASME J. Heat Transfer, 91, pp. 434–441)

Discussion: “Heat Transfer and Pressure Drop in Tape-Generated Swirl Flow of Single-Phase Water” (Lopina, R. F., and Bergles, A. E., 1969, ASME J. Heat Transfer, 91, pp. 434–441)