Initial Flow Behavior in Laminar Line Source Twin Plumes of Equal Strength

We present two-dimensional direct numerical simulations for two laminar line source plumes of equal strength, which are placed side by side at the same level, in an open surrounding, with the supply of constant heat flux at the heat sources. We have performed the simulation for the effective Rayleigh number (based on constant heat flux supplied at the heat source) \(1 \times 10^{6}\) and Prandtl number 7, for different source separations as 2D, 3D, 4D, 5D, 6D, and equivalent single plume, where D is the diameter of the cylindrical heat source. We observed that with the increase in source separations, the plume ejects more mass sideways after merging, which leads to an increase in the heat transfer in the lateral direction in a quadratic fashion. Also, for larger source separations, the merged plume becomes more stable and hence rises with lesser fluctuations in vertical velocities.