Interfacial flow computations using adaptive Eulerian–Lagrangian method for spacecraft applications

Abstract

SUMMARY Understanding the interfacial dynamics and fluid physics associated with the operation of spacecraft is important for scientific as well as engineering purposes. To help address the issues associated with moving boundaries, interfacial dynamics, and spatial‐temporal variations in time and length scales, a 3‐D adaptive Eulerian–Lagrangian method is extended and further developed. The stationary (Eulerian) Cartesian grid is adopted to resolve the fluid flow, and the marker‐based triangulated moving (Lagrangian) surface meshes are utilized to treat the phase boundary. The key concepts and numerical procedures, along with the selected interfacial flow problems are presented. Specifically, the liquid fuel draining dynamics in different flow regimes, and the liquid surface stability under vertically oscillating gravitational acceleration are investigated. Direct assessment of experimental measurement and scaling analysis is made to highlight the computational performance of the present approach as well as the key fluid physics influenced by the given flow parameters. Copyright © 2010 John Wiley & Sons, Ltd.

A computational study of droplet evaporation with fuel vapor jet ejection induced by localized heat sources

“…In this study, a marker-based Eulerian-Lagrangian method 31 is implemented with a temperature-dependent surface tension model and a local phase change model to predict the thermo-capillary flow and the droplet evaporation rate. The method is chosen in favor of its accurate interface representation and explicit tracking.…”

“…The details of the algorithm can be found in the previous study. 31 The adaptive algorithm is further refined by implementing different AMR levels and layers for each region. Figure 3 shows an example of the AMR in the present simulation.…”

A Computational Study of Internal Flows in a Heated Water-Oil Emulsion Droplet

“…The flow fields in an emulsion droplet with Hill's vortex and heat transfer from evaporating surface is simplified by assuming constant velocity-and temperature-gradient. As a preliminary simulation, a 2-D computation with a cylindrical micro-droplet was conducted by implementing the Eulerian-Lagrangian method 10 with a temperature-dependent surface tension model. The surface temperature is assumed 373.12 K, which is the boiling temperature of water at the given pressure of 0.1 MPa.…”

“…It is known that the interface tracking and surface tension computations are more accurate and efficient in Eulerian-Lagrangian method than Eulerian method at the same level of grid resolutions. 9,10 The immersed boundary method proposed by Peskin is categorized in this method. 11 Sim et al implemented succefully this Eulerian-Lagrangin method for modeling of a droplet evaporation by local heating and showing the fuel vapor jet ejection induced by Marangoni effect.…”

“…12 In the present study, a water-oil emulsion droplet on a hot surface was considered. As a simplified numerical modeling, a 2-D cylindrical micro-droplet movement in an emulsion droplet with velocity and temperature gradient was simulated in a 2-D computational doamin by implementing the Eulerian-Lagrangian method 10 with temperaturedependent surface tension model. The micro-droplet movement mechanism, in which micro-droplets always move to surface and vaporize first, was investigated by analyzing the interfacial dynamics around micro-droplets and parametric studies on the micro-droplet size and temperature gradient were followed.…”