Research Description

Savio J. Poovathingal Department of Mechanical Engineering, University of Kentucky

Microscale processes in gas-surface interactions

The broad theme in this research thrust is to understand the various thermochemical processes occurring in ablative (and reusable) heat shield materials at the small scales and building macroscale models for use in computational ﬂuid dynamics (CFD) and material response codes. Within the context of small scales, my group investigates in-depth processes occurring within the microstructures of heat shield materials. A major thrust in this research space is to quantify the in-depth radiative heating of heat shield materials. Experimental data and inverse ﬂight estimation of Avcoat from ﬂight tests indicate that radiation penetrates deep into the TPS material, and it is not just a surface heating process. The governing equation and discretization of the radiative transport equation is fairly straightforward and can be easily included into state-of-the-art material response codes. However, radiation transport is extremely sensitive and inherently depends on the absorption and extinction coeﬃcients that are a function of wavelength of light penetrating through the heat shield material. These absorption and extinction coeﬃcients for the heat shield materials are unknown. In this eﬀort, we are developing a new high-ﬁdelity advanced Monte Carlo radiation (AMCR) solver that will be used to compute the eﬀective absorption and extinction coeﬃcients over a wide range of wavelengths for relevant heat shield materials (PICA/Fiberform, SLA-220). Speciﬁcally, we will simulate the transport of photons through the microstructures of heat shield materials to quantify the required coeﬃcients.

Collaborators

Drs. Aaron Brandis and Eric C. Stern (NASA Ames Research Center), Prof. Alexandre Martin (Department of Mechanical Engineering, U of Kentucky).

Students

Ayan Banerjee (Ph.D. student)

Brendan Soto (Ph.D. student)

Tyler Stoffel, Graduate

Vincenzo Russo

Ares A Barrios-Lobelle, Graduate added 11/24/2020

Raghava Sai Chaitanya Davuluri, added 11/24/2020

Cam E Brewer, added 12/07/2020

Luis Chacon Olivar, Added 05/18/2021

Ethan H Huff, Added 06/02/2021

Vijay B Mohan Ramu, Added 08/17/2021

Austin F Major, Added on LCC, 01/12/2022

Ahmed Yassin, Added on LCC, 02/08/2022

Ben D Deaton, Added on LCC, 03/24/2022, Added on MCC 05/11/2022

John Patton, Added on LCC, 06/25/2022

Evan Wells, Added on 09/07/2022 on LCC resources

Ethan H Huff, Added on 09/18/2022 on MCC resources

Christian Lauritzen, Added on 10/28/2022 on LCC Resources

Vijay Mohan-Ramu, Added on 03/22/2023 on MCC Resources

Luis Chacon-Olivar, Graduate, Added on MCC Resources, 05/06/2023

Brendan M Soto, Added on 05/08/2023 on MCC Resources

Luis Chacon-Olivar, Graduate, Added on MCC resources 05/08/2023

Tyler D Stoffel, Graduate, Added on MCC resources 06/19/2023

Braden K Bybee, Added on MCC resources 07/18/2023

Ayan Banerjee, Added on MCC resources 07/18/2023

Ahmed H Yassin, Graduate, Added on MCC resources 07/26/2023

Pouya Samanipour, Graduate, Added on MCC resources 08/11/2023

Ahilan Appar, Postdoc, Added on MCC resources 08/11/2023

Software

It is an in-house designed code in C++ that uses OpenMPI libraries for inter-processor communication. The code also has capabilities to run on GPU nodes. Based on some limited scalability study, we estimate parallel scalability up to 2,000 cores.

Capturing melt ﬂow in high-temperature environments for CFD codes

Melting of coatings on surfaces is ubiquitous when surfaces are exposed to high-temperature ﬂow environments. Under the pressure and shear stresses from the ﬂow, the melt ﬂow eventually begins to ﬂow over the sample creating ripples and waves along the surface. While the scientiﬁc community has advanced framework to handle gas-solid interactions, there is no computational framework to handle the ﬂow of molten liquid in hypersonic CFD simulations. In this eﬀort, we are trying to build a computational framework to capture the ﬂow of molten liquid that interacts with a hypersonic ﬂow environment.

Collaborators

Drs. Justin Haskins and Eric C. Stern (NASA Ames Research Center).

Students

Tyler Stoﬀel (Ph.D. student)

Camereon E Brewer, Added on MCC cluster on 05/11/2022

Bruno Domingues Tacchi, Added on MCC cluster on 05/13/2022

Blaise Frasure, Added on MCC cluster on 6/15/2022

Software

New capabilities are being added to the open-source SU2 CFD code which is written in C++ and uses OpenMPI libraries for inter-processor communication.

Expertise and Capabilities

Dr. Poovathingal leads the computational thermophysics and ﬂuids laboratory (CTFL) at the University of Kentucky. He brings expertise in high-ﬁdelity modeling of non-equilibrium gas-surface processes in hypersonic entry, radiative Monte Carlo and direct simulation Monte Carlo (DSMC) techniques, plasma dynamics in hypersonic ﬂight, and molecular dynamics for engineering applications. The tools available in CTFL group are • Monte Carlo radiation code. • direct simulation Monte Carlo code. • Multi-physics CFD code.

Grants

Publications

Patents

Browser not supported