共查询到8条相似文献,搜索用时 62 毫秒
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论述了平面粘性液体层喷射进入可压缩气流中的线性稳定性。根据液体、气体的质量和动量守恒,推导出了Temporal、Convective和Absolute不稳定雾化模型的各种特性方程,其解具有二种形式:para-sinuous和para-varicose。 相似文献
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可压缩气流中平面液体层雾化的线性稳定性理论推导(英) 总被引:2,自引:0,他引:2
论述了平面粘性液体层喷射进入可压缩气流中的线性稳定性。根据液体、气体的质量和动量守恒,推导出了Tem poral、Convective 和Absolute 不稳定雾化模型的各种特性方程,其解具有二种形式:para-sinuous和para-varicose。 相似文献
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驻波作为薄液膜表面波中的一种波,其流动稳定性受界面热不平衡效应的影响。基于边界层理论和界面热不平衡效应,推导出沿倾斜璧面下降的在蒸发、等温和冷凝状态下普遍适用的二维表面驻波空间稳定性方程,从理论上深入分析了热不平衡效应、流体物性、壁面倾角和雷诺数对驻波稳定性的影响。研究表明:热不平衡效应对驻波稳定性的影响仅在小雷诺数下较为明显,在高雷诺数下,稳定性主要取决于惯性力和粘性力;流体物性和壁面倾角在整个雷诺数范围内均起着非常明显的作用。 相似文献
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An experimental study on gas absorption into falling liquid film formed on inner surface of vertical tubes has been carried out in order to clarify fundamental characteristics of the gas absorption and enhancement by surface waves. The water supplied into the test tubes is periodically disturbed by fluctuating a silicon tube before the test section with a speaker and the wavy films absorb the oxygen filled in the tubes. Imposing the periodic disturbance enhances the gas absorption and the enhancement has a maximum at around 20-30 Hz, where the gas absorption is 20-30% higher. Mass transfer coefficients obtained with five tubes agree well with those obtained with single tube. Two-dimensional numerical simulations have also been conducted for gas absorption by wavy film and the enhancement mechanism of the gas absorption is discussed. 相似文献
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When a liquid film is under the evaporating or condensing condition, the flow stability is clearly different from that under an isothermal condition due to the thermal non‐equilibrium effect at the interface, especially under a lower Reynolds number. Based on Prandtl's boundary layer theory and complete boundary conditions, the universal temporal and spatial stability formulations are established using the collocation method for two‐dimensional surface waves of the evaporating or condensing and isothermal liquid films draining down an inclined wall. The evolution equations indicate that the flow stability is closely related to the Reynolds number, thermocapillarity, inclination angle, liquid property, and evaporation, isothermal, or condensation actions. The effects of the above factors are investigated with neutral stability curves at different Reynolds numbers, and stability characteristics are fully indicated in theory for evaporating or condensing films. Results show that the evaporation process destabilizes the film flow and condensation process stabilizes the film flow. Thermocapillarity has a stabilizing effect in an evaporation condition and an adverse effect in the condensation condition. For a lower Reynolds number, the vapor recoil and thermocapillary take dominant effects when compared to the inertia force in determining flow stability. At a higher Reynolds number, the flow stability is controlled by the inertia force. Present study indicates that the disturbance increases with an increase of the Reynolds number and inclination angle, and decreases with increase of Ka numbers. Furthermore, the effects of liquid properties and inclination angle are always significant. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(4): 243–257, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20062 相似文献
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为研究正弦波形填料基底上液膜的流动、传热特性及不同结构该基底的冷却效果对电厂热经济性的影响,通过建立合理的物理模型,运用Fluent软件对不同振幅、波长和倾斜角度条件下正弦波形填料基底上的冷却液膜进行了数值模拟.以数值模拟的出口水温为计算依据,通过热力计算分析了不同正弦波基底结构对全厂热经济性指标的影响.结果表明:倾斜角度、振幅不变时,随着波长的增加,基底上液膜的厚度变薄,出口水温升高;波长、振幅不变时,倾斜角度的增大使得基底上液膜的厚度增加,出口水温降低;倾斜角度、波长不变时,随着振幅的增大,基底上液膜的厚度变厚,出口水温降低. 相似文献