Study of Conjugate Heat Transfer in Electromagnetic Liquid Metal Dream Pipe

Abstract

The combined effect of conjugation, external magnetic field and oscillation on the enhancement of heat transfer in the laminar flow of liquid metals between parallel plate channels is analyzed. In order to make our results useful to the design engineers, we have considered here only the wall materials that are widely employed in liquid metal heat exchangers. Indeed, all the results obtained through this mathematical investigation are in excellent agreement with the available experimental results. The effective thermal diffusivity κ e is increased by 3 · 10 6 times due to oscillation and that the heat flux as high as 1.5 · 10 10 (W/m 2 ) can be achieved. Based on our investigation, we have recommended the best choice of liquid metal heat carrier, wall material and its optimum thickness along with the optimum value of the frequency to maximize the heat transfer rate. At the optimum frequency, by choosing a wall of high thermal conductivity and optimum thickness, an increase of 19.98% in κ e can be achieved. Our results are directly relevant to the design of a heat transfer device known as electromagnetic dream pipe which is a very recent development.

A Dramatic Enhancement of Heat Transfer in Dream Pipe with Viscoelastic Fluids

“…2,4,6). This result is similar to the result we have observed in the Newtonian case(Puvaneswari and Shailendhra 2017b). The maximum value of * e  observed in this case is 0.039 when RM = 0.4 and the wall material is stainless steel.…”

“…For a given temperature gradient γ, It should be noted here that, Kurzweg (Kurzweg 1985b) obtained a high heat flux of 1.8 x 1010 W/m 2 using pressurized water when ω = 300 rad/s. In our earlier work (Puvaneswari and Shailendhra 2017b) with liquid metals, we were able to achieve such a high heat flux for ω = 300 rad/s only when ∆x = 3.1 m. Here also if we choose such a large value for ∆x instead of ∆x = 1 m, we can achieve a high heat flux of 1.56 x 10 10 W/m 2 for the fluid Na with the wall material Ni which is two orders of magnitude higher than that obtained with ∆x = 1 m.…”