Numerical Simulation of the Atomization Process of a Like-doublet Impinging Rocket Injector

Abstract

A numerical simulation is conducted to characterize the atomization process of like-doublet injector with two different impingement angles. Using the coupled Level-Set/Volume-of-Fluid (CLSVOF) method for capturing the liquid/gas interfaces, liquid sheet characteristics were efficiently captured, and the simulations were found to agree well with experiment results for both breakup characteristics and Sauter Mean Diameter (D 32 ). This method combines the mass conservation properties of the volume-of-fluid method with the accurate surface reconstruction properties of the Level-Set method for a 3D atomization process simulation of the like-doublet injector. Since the velocity profiles around the stagnation point and impingement point greatly affects the sheet characteristics, the velocity profiles of different axial locations on the cross section for two different impingement angles cases are studied. It shows that the velocity difference caused by the impact of liquid jets is one of the important factors which directly affect the formation of surface wave and the breakup of sheet

Characterization of Liquid Impinging Jet Injector Sprays for Bi-Propellant Space Propulsion: Comparison of PDI and High-Magnification Shadowgraphy

“…And yet, as Z increases, the characteristic diameter computed from the drop size distribution has distinct behaviours in other work: SMD increases [5]- [6] or decreases [3] with increasing distance from the impingement point. Therefore, a characteristic diameter should be evaluated to quantify this effect.…”

“…at elevated Reynolds and Weber numbers (10 3 -10 4 ) leading to ligaments and fully developed breakup; a review of such spray phenomena can be drawn from detailed experiments [1]. Like-impinging doublets are investigated through theoretical studies [2] and numerical simulation [3]- [4], highlighting the dynamics of the liquid sheet breakup that generates wavy ligaments and then droplets. However in this complex situation, the reference knowledge concerning the spray shape, the distribution of droplet size and velocity, is provided by experiments [5]- [8]; for this purpose, most studies are based on PhaseDoppler Interferometer (PDI) and direct visualization of the spray.…”

“…This makes spray combustion all the more complex because drop size influences combustion performance and induction length, as an example. Moreover, the Sauter Mean Diameter (SMD) measured with PDI is found to increase with increasing distance from the impingement point [5]- [6], whereas it is found to decrease in another study combining experiment and simulation [3]. This contradiction shows that impinging jet sprays deserve a specific study, in order to discuss the methods used to analyse the structure of such sprays.…”

Numerical investigation on the impingement of spraying jet by an improved smoothed particle hydrodynamics method

“…Violent impingement is usually accompanied by strong discontinuity phenomena with instantaneous high pressure and breakup of the fluid surface, which is difficult for traditional grid-based numerical methods to deal with impinging flow problems. Therefore the volume-of-fluid method [5][6][7][8] and Level Set [9,10] are introduced to track the movement of free surfaces or interfaces, which will lead to a large computing cost. Therefore, the meshless method was introduced to solve the problems with complex boundary actions or large deformation [11,12].…”