Numerical Computation for Buoyancy Effect on Three-Dimensionality and Vortex Dislocation in Heated Wake with Vertical Mainstream

Direct Numerical Simulation of Isothermal Wake: DNS Noise, Strong Anisotropy Turbulence, and Vortex Dislocation Generation Mechanism

“…Studies of the 3-D motion, oscillation mode, and vortex dislocation have been presented previously [3,4]. The vortex dislocation has been studied mainly in the isothermal wake.…”

“…The vortex dislocation has been studied mainly in the isothermal wake. The formulations and the numerical methodology were given in [3], and the computed streaklines, vortex dislocation generation, and oscillation mode were discussed in [4]. imaginary, or numerical order of time-series data j jdirection (x, y, or z direction is at j ¼ 1, 2, or 3) N number of data of sampling p pressure P(f) power spectrum density ¼ R CðsÞ expðÀi2pf sÞ ds  à p(g) probability density function…”

Cooled Vortex Street with Large Vortex Spirals Generated by Cooling a Circular Cylinder at Low Reynolds Number: Effects of Fluid Kinds on Wake Patterns

“…The isothermal wavy wake at Re ¼ 44 is 2-D, because an isothermal wake at Re < 180 is 2-D [27]. In fact, the wake at Re ¼ 300 is 3-D [9,10]. The 2-D assumption is also valid in the cooled Karman vortex street, transitional wake to the cooled vortex street, cooled vortex street, and transitional wake to the symmetric wake at Re ¼ 44 as shown earlier, because the cooled vortex street visualized experimentally at Re ¼ 60 is 2-D [25].…”

“…Recently, the much complicated 3-D vortex dislocation, which occurs in the early stage to the turbulent flow, and its control by the near-wake heating have been studied in air by Direct Numerically Simulation (DNS) in [9,10]. Furthermore, the 3-D transition around a heated cylinder in a horizontal mainstream of water has been studied in [11].…”

“…Furthermore, the 3-D transition around a heated cylinder in a horizontal mainstream of water has been studied in [11]. Here, a mixed convective flow in [9][10][11] is combined with the natural convection and the forced convection, and depends on fluid kinds. However, effects of fluid kinds, e.g., mercury, air, water, etc., on the thermo-fluid behavior in a mixed convective flow have not been elucidated.…”