【摘要】 水力空化对于强化化学反应、提高化学产率方面具有重要意义。为了探究粗糙度对文丘里管内空化流动特性的影响,采用雷诺时均N-S方程、标准k-ε方程和ZGB空化模型建立了数值计算模型,通过分析文丘里管内汽含率分布及湍动能的变化,研究粗糙度对内部空化流场的影响规律。计算结果表明:从全管段粗糙度考虑,粗糙度较大时增加了流动沿程压力损失从而抑制了空化强度;而仅考虑某段粗糙度时,粗糙度会通过增加内壁附着的微气核数量来强化空化效应,且渐扩段粗糙度为0.006 4 mm时强化效果最佳。更多还原

【Abstract】 Hydraulic cavitation is of great significance for the chemical reaction rate and chemical yield improvement. In order to explore the effect of roughness on cavitation flow characteristics in venturi tube, the neynolds N-S equation, standard k-ε equation and ZGB full cavitation model were used to establish the numerical calculation model. By analyzing the distribution of vapor volume fraction and the change of turbulent kinetic energy in venturi, the influence of roughness on the cavitation flow field was studied. The results showed that considering the roughness of the whole pipe, the pressure loss along the flow path increased when the roughness was large, thus the cavitation intensity was suppressed. When considering the roughness at only a certain location, the roughness would increase the number of micro-gas nuclei attached to the inner wall to strengthen cavitation, and the optimization effect was the best when the roughness of the gradually expanding section was 0.006 4 mm.更多还原