Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Numerical Simulation of Full-cone Sprays for Liquid Film Formation
Submission Author:
Marcus Vinícius Pedron Carneiro , SC
Co-Authors:
Júlio César Alves Ferreira, Marcus Vinícius Pedron Carneiro, Jader Riso Barbosa Jr.
Presenter: Júlio César Alves Ferreira
doi://10.26678/ABCM.COBEM2023.COB2023-1256
Abstract
In this study, we offer a brief overview on full-cone spray modeling. A system of coupled ODEs based on bal- ances of mass, momentum, and energy is used to resolve the spray transport and atomization. An experimental apparatus with a novel 3-colliding jets spray configuration in a vapor-compression refrigeration system is presented in detail. In prior research, we conducted experiments to evaluate spray and jet impingement as cooling schemes for high heat flux applications. The proposed technology integrates the functions of the expansion device and evaporator of a miniatur- ized, oil-free refrigeration system into a single unit. The two-phase flow inside the cooling unit involves high-pressure subcooled liquid refrigerant entering a jet/spray cooling unit and expanding in one or more orifices, resulting in the formation of either spray or free liquid jets (depending on experimental conditions and setup). These jets then impinge on a heated surface, facilitating convective boiling and evaporation of the liquid film, thereby removing heat. This ap- proach capitalizes on the high heat transfer coefficients of spray and impinging jet, as well as the below-ambient junction temperature of the refrigeration loop. As a result, the compact heat sink has the potential to be applied in numerous vapor-compression cooling systems, including those for power electronics and thermal management of batteries. The full-cone spray model for refrigerant R-134a is compared with different datasets from the literature finding a very good agreement for both the Gaussian droplet velocity radial distribution and the droplet centerline axial velocity away from the injector. The impact velocity is a very important parameter used to determine the liquid film formation and liquid film thickness at the heated surface. Additionally, the full-cone spray model is used for the 3-colliding jets configuration, providing satisfactory results.
Keywords
spray cooling, Jet Impingement, CFD, Oil-free Compressor, Vapor Compression refrigeration System
