Kinetic energy efficiency of atomizing air,by C is the ratio of the effective energy required for atomization to the kinetic energy of the atomizing air.The present study analyzes the variation of C with the Reynolds ...Kinetic energy efficiency of atomizing air,by C is the ratio of the effective energy required for atomization to the kinetic energy of the atomizing air.The present study analyzes the variation of C with the Reynolds number of atomazing air stream,Ohnesorge number and air to liquid mass ratio. Atomization of non-Newtonian fluids with viscosity up to 4.4 Pa·s is carried out by using a specially designed prefilming airblast atomizer. Drop sizes are measured by using laser diffraction technique. For liquids with low viscosities,impingement of air stream on the liquid film dominates the atomization process and film thickness exercises only minor influence on C ; while for liquids with high viscosities,disintegration of liquid film is made by the impingement of air stream on the liquid film and the wavy movement of film,and C is higher for thinner liquid film in the same operation conditions.The shear force on the surface of liquid film formed by swirling atomizing air plays an important role in the atomization of film in the conditions of low air velocities and low liquid viscosities and its influence on atomization gradually weakens with increasing atomizing air velocity and liquid viscosity.Eventually impinging on the liquid film dominates the atomization process.展开更多
The main purpose of this article is to present a mathematical model of ciliary motion in an annulus. In this analysis, the peristaltic motion of non-Newtonian Jeffrey six constant fluid is observed in an annulus with ...The main purpose of this article is to present a mathematical model of ciliary motion in an annulus. In this analysis, the peristaltic motion of non-Newtonian Jeffrey six constant fluid is observed in an annulus with ciliated tips in the presence of heat and mass transfer. The effects of viscous dissipation are also considered. The flow equations of non-Newtonian fluid for the two-dimensional tube in cylindrical coordinates are simplified using the low Reynolds number and long wave-length approximations. The main equations for Jeffrey six constant fluid are considered in cylindrical coordinates system. The resulting nonlinear problem is solved using the regular perturbation technique in terms of a variant of small dimensionless parameter α. The results of the solutions for velocity, temperature and concentration field are presented graphically. B_k is Brinkman number, ST is soret number, and SH is the Schmidth number. Outcome for the longitudinal velocity, pressure rise, pressure gradient and stream lines are represented through graphs. In the history, the viscous-dissipation effect is usually represented by the Brinkman number.展开更多
文摘Kinetic energy efficiency of atomizing air,by C is the ratio of the effective energy required for atomization to the kinetic energy of the atomizing air.The present study analyzes the variation of C with the Reynolds number of atomazing air stream,Ohnesorge number and air to liquid mass ratio. Atomization of non-Newtonian fluids with viscosity up to 4.4 Pa·s is carried out by using a specially designed prefilming airblast atomizer. Drop sizes are measured by using laser diffraction technique. For liquids with low viscosities,impingement of air stream on the liquid film dominates the atomization process and film thickness exercises only minor influence on C ; while for liquids with high viscosities,disintegration of liquid film is made by the impingement of air stream on the liquid film and the wavy movement of film,and C is higher for thinner liquid film in the same operation conditions.The shear force on the surface of liquid film formed by swirling atomizing air plays an important role in the atomization of film in the conditions of low air velocities and low liquid viscosities and its influence on atomization gradually weakens with increasing atomizing air velocity and liquid viscosity.Eventually impinging on the liquid film dominates the atomization process.
基金Supported by the National Natural Science Foundation of China(10231060,10501024)the Specialized Research Fund of Doc-toral Program of Higher Education of China(20040319003)+1 种基金the Natural Science Fund of Jiangsu Province(BK2006214)the Key Subject Fund of Nanjing Normal University
文摘The main purpose of this article is to present a mathematical model of ciliary motion in an annulus. In this analysis, the peristaltic motion of non-Newtonian Jeffrey six constant fluid is observed in an annulus with ciliated tips in the presence of heat and mass transfer. The effects of viscous dissipation are also considered. The flow equations of non-Newtonian fluid for the two-dimensional tube in cylindrical coordinates are simplified using the low Reynolds number and long wave-length approximations. The main equations for Jeffrey six constant fluid are considered in cylindrical coordinates system. The resulting nonlinear problem is solved using the regular perturbation technique in terms of a variant of small dimensionless parameter α. The results of the solutions for velocity, temperature and concentration field are presented graphically. B_k is Brinkman number, ST is soret number, and SH is the Schmidth number. Outcome for the longitudinal velocity, pressure rise, pressure gradient and stream lines are represented through graphs. In the history, the viscous-dissipation effect is usually represented by the Brinkman number.
