Fig. 1: Comparison of experimental and predicted Nusselt numbers in a three-legged passage for Re=25,000, and Ro=0, Ap/p=0.12

The following simulations are ongoing, and are at various degrees of completion.

1. Flow and heat transfer in channels of aspect ratio of 1:4 and 4;1, for a wide range of buoyancy parameters, and Re and Ro numbers. Representative results are presented below. Detailed results on these simulations will be presented in the upcoming contractors meeting in Feb.

« 1by1 Experiment 1by1 Simulated —*— 1by4 simulated >< 4by1 simulated

Figure 2: Nusselt number for 1:1, 1:4, and 4:1 aspect ratios, Re=25000, Ro=0, Ap/p=0.12

The streamwise distributions of the average Nusselt number in the three radial passages for the 1:1, 1:4, and 4:1 cases are shown in Fig. 2 above. Lowest heat transfer rates are observed for the 1:4 case, while the square and 4:1 cases show comparable rates.

With rotation, both the 1:4 and 4:1 cases exhibit the behavior observed for the 1:1 case, that is, enhanced heat transfer (relative to the stationary channel) along the trailing surfaces of the radially-outward flow leg, and leading surfaces of the radially-inward flow leg (see Fig. 3 below). These differences are greater for the 1:4 case as seen in Fig. 3.

Figure 3: Nusselt number for the 1:4 aspect ratio case, Re=25000, Ro=0.23, Ap/p=0.12
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