"High-Fidelity CFD Simulations of Rotor-in-Hover: New Tools & Insights"

17 March 2023
12:00 pm to 1:00 pm
"High-Fidelity CFD Simulations of Rotor-in-Hover: New Tools & Insights"
Nathan Hariharan
Chief Scientist & Technologist
DoD High Performance Computing Modernization Program (HPCMP)

Abstract:  Wake breakdown is a well-documented computational phenomenon associated with highly resolved computational hover predictions. As the computational state-of-the-art for hover predictions has progressed, allowing for higher resolution of the rotor wake, the formation of secondary braids in computed helical wake systems has manifested in various forms. The formation of 3D secondary braids between two parallel convecting vortex filaments, under the right conditions, is physical. Recent hi-definition rotor-hover experiments do confirm their presence. However, computed wake breakdown is more pervasive, and the question of whether high-fidelity methods exaggerate the extent of the secondary vortex production has been a topic of research in the past decade. In this talk, interesting recent developments are highlighted. Specifically, two technological tools that enhance the understanding of computed hover vortex dynamics & breakdown are discussed: (i) Direct Volume visualization of computed hover wake vortex dynamics and (ii) Machine Learning-Based automated identification of computed wake breakdown. Direct volume rendering provides insights into the wake breakdown vortical interplay. The automation of vortex-breakdown identification using Machine Learning accelerates the process of physics discovery and provides a hover solution quality alerting mechanism for engineering use-cases.

The talk will also give a brief overview of DoD HPCMP CREATE program and the AIAA Hover Prediction Workshop.


Bio:  Dr. Hariharan is the  Chief Scientist & Technologist for the DoD High-Performance Computing Modernization Program’s (HPCMP) Computational Research Engineering Acquisition Tools and Environments (CREATE) initiative comprising of Air, Land, and Sea Vehicles, Antennas, and cross-cutting Foundational Technologies components. The CREATE program has produced several widely[1]deployed flagship HPC software suite products with over 4000 licenses across DoD, NASA, DoE and the defense industry. Dr. Hariharan is also one of the world's leading experts in rotorcraft flowfield modeling and simulation. In recent years, Dr. Hariharan has pioneered the automation of physics inference in large-scale computational simulations using AI/Machine Learning methods. Dr. Hariharan is the founder and chair for the AIAA Rotorcraft Hover Working Group. Dr. Hariharan has brought together leading industry, government (DoD, NASA), and academic participants worldwide to assess and further the state-of-the-art in the modeling and simulation of rotorcraft in hover through the AIAA Hover Prediction Workshops (https://www.aiaa-hpw.org).