並進運動に伴う球形液滴周りの減圧挙動に対する微小慣性の影響 : 第2報,直接数値シミュレーションによる理論の検証(流体工学,流体機械)

抄録

A dimensionless number "C_TDP", which corresponds to the dimensionless pressure reduction due to the translational motion of a drop scaled by the fluid density and the translational velocity, is numerically investigated. Sufficiently small but non-zero Reynolds number "Re" cases are investigated in order to verify the theory given in the 1st report. Direct Numerical Simulation (DNS) of a flow around a spherical drop is carried out for various Reynolds numbers and viscosity ratios between interior and exterior fluids of the drop. The effect of the computational domain size on the drag coefficient, C_TDP and the velocity profile in the far field is discussed in order to obtain the perturbed components of C_TDP by Re with high accuracy and the outer boundary of computational domain is set to be about 1000 bubble raii. The C_TDP obtained by the DNS shows good agreement with that by the method of matched asymptotic expansions up to the term of order Re² log Re shown in the 1st report.