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Daoru Han

Publications and source records attributed to Daoru Han.

2 recordsLinked to original sources

Understanding and Mitigating Plume Effects During Powered Descents on the Moon and Mars

This 2020 Decadal Survey White Paper reviews what is known about lunar and martian lander Plume Surface Interactions (PSI) during powered descent. This includes an overview of the phenomenology and a description of the induced hardware and environmental impacts. Then it provides an overview of mitigation techniques and a summary of the outstanding questions and strategic knowledge gaps. It finishes with five recommendations: to include dedicated descent imagers on every surface mission so that PSI can be directly recorded and reviewed by ground teams; as far as possible, to make all data related to PSI effects publicly accessible; to develop methods and instruments for making key measurements of PSI; to assess and record key flight data; and to invest funding into studies of long-term infrastructure architectures and mitigation techniques.

astro-ph.IM

PIFE-PIC: Parallel Immersed-Finite-Element Particle-In-Cell For 3-D Kinetic Simulations of Plasma-Material Interactions

This paper presents a recently developed particle simulation code package PIFE-PIC, which is a novel three-dimensional (3-D) Parallel Immersed-Finite-Element (IFE) Particle-in-Cell (PIC) simulation model for particle simulations of plasma-material interactions. This framework is based on the recently developed non-homogeneous electrostatic IFE-PIC algorithm, which is designed to handle complex plasma-material interface conditions associated with irregular geometries using a Cartesian-mesh-based PIC. Three-dimensional domain decomposition is utilized for both the electrostatic field solver with IFE and the particle operations in PIC to distribute the computation among multiple processors. A simulation of the orbital-motion-limited (OML) sheath of a dielectric sphere immersed in a stationary plasma is carried out to validate PIFE-PIC and profile the parallel performance of the code package. Furthermore, a large-scale simulation of plasma charging at a lunar crater containing 2 million PIC cells (10 million FE/IFE cells) and about 520 million particles, running for 20,000 PIC steps in about 109 wall-clock hours, is presented to demonstrate the high-performance computing capability of PIFE-PIC.

cs.MS