Session: 06-01: Spray Modeling

Paper Number: 141709

141709 - Modelling Heat Generation in Glow Plug and Cooling Due to Droplet Impact 

Abstract: 

In modern aviation, reliable ignition assistance technologies are imperative for ensuring optimal fuel adaptability in combustion engines, particularly within various military propulsion systems like unmanned aerial vehicles. Incorporating hot surface energy injection can significantly enhance engine performance. Smoothed particle hydrodynamics (SPH) has emerged as a valuable tool over the last decade for studying thermo-fluid problems. SPH discretizes the domain with a scattered set of particles, each representing physical quantities such as mass, density, and temperature. Through interactions among these particles, field variables are computed smoothly. However, SPH's lack of anisotropic discretization in its standard form presents computational challenges. To address this, we developed a Graphics Processing Unit (GPU) accelerated SPH solver within the Compute Unified Device Architecture (CUDA) framework. This model allows for the study of temperature distribution and thermal stresses in realistic hot surface ignition devices. The developed model is validated against experiments for the heating of the hot surface ignition device under engine-relevant conditions. Parametric studies are conducted to analyze temperature and thermal stress responses for different ceramic materials used in the construction of the glow plug. In parametric studies ceramic sheath is modeled using silicon nitride, alumina, and sialon and the heating element is taken to be tungsten carbide. Preliminary tests indicate that the sialon sheath is expected to exhibit higher temperatures and thermal stresses. Subsequently, droplet impact simulations are integrated into the solver to simulate cooling of the glow plug due to fuel injection. The temperature and thermal stress fields during fuel droplet impact on the ignition assistant device are evaluated. The thermal stress fields exhibit higher values in proximity to the heating element. Additionally, the impact of droplets leads to a temperature decrease near the outer surface, consequently causing an elevation in thermal stress levels. In conclusion, this study provides valuable insights for the development of glow plugs and enables the prediction of temperature and thermal stresses experienced by them across different heat generation rates and materials.

Presenting Author: Song-Charng Kong Texas Tech University

Presenting Author Biography: The presenter is a second-year PhD student in mechanical engineering at Texas Tech University. He received his bachelor's degree in aerospace engineering from Sharif University of Technology in Iran. His current research area is in Computational Fluid Mechanics (CFD) using Smoothed Particle Hydrodynamics (SPH).

Authors:

Kamyab Karimi Texas Tech University
Doruk Isik Texas Tech University
Song-Charng Kong Texas Tech University
Eric Mayhew DEVCOM, Army Research Laboratory
Kenneth S. Kim DEVCOM, Army Research Laboratory
Chol-Bum M. Kweon DEVCOM, Army Research Laboratory