Abstracts Engineering

Add abstract

Want to add your dissertation abstract to this database? It only takes a minute!

Search abstract

Search for abstracts by subject, author or institution

Share this abstract

Flame spread over thick polymethylmethacrylate samples in a simulated and actual microgravity environment

by Tirthesh Jayesh Shah

Institution: San Diego State University
Year: 2016
Posted: 02/05/2017
Record ID: 2135613
Full text PDF: http://hdl.handle.net/10211.3/177350


Abstract

The NASA Burning and Suppression of Solids-II (BASS II) experiment examines the combustion of different solid materials and material geometries in microgravity. While flames in microgravity are driven by diffusion and weak advection due to crew movements and ventilation, the current NASA spacecraft material selection test method (NASA-STD- 6001 Test 1) is driven by buoyant forces as gravity is present. The overall goal of this project is to understand the burning of intermediate and thick fuels in microgravity, and devise a normal gravity test to apply to future materials. Clear cast polymethylmethacrylate (PMMA) samples 10 cm long by 1 or 2 cm wide with thicknesses ranging from 1-5 mm were investigated. PMMA is the ideal choice since it is widely used and we know its stoichiometric chemistry. Tests included both one sided and two sided burns. Samples are ignited by heating a wire behind the sample. The samples are burned in a flow duct within the Microgravity Science Glovebox (MSG) on the International Space Station (ISS) to ensure true microgravity conditions. The experiment takes place in opposed flow with varying Oxygen concentrations and flow velocities. Flames are recorded on two cameras and later tracked to determine spread rate. Currently we are modeling combustion of PMMA using Fire Dynamics Simulator (FDS 5.5.3) and Smokeview. The entire modelling for BASS-II is done in DNS mode because of the laminar conditions and small domain. In DNS mode the Navier Stokes equations are solved without the Turbulence model. The model employs the same test sample and MSG geometry as the experiment; but in 2D. The experimental data gave upstream velocity at several points using an anemometer. A flow profile for the inlet velocity is obtained using Matlab and input into the model. The flame spread rates obtained after tracking are then compared with the experimental data and the results follow the trends but the spread rates are higher. Advisors/Committee Members: Miller, Fletcher, Bhattacharjee, Subrata, Liu, Xiaofeng.

Add abstract

Want to add your dissertation abstract to this database? It only takes a minute!

Search abstract

Search for abstracts by subject, author or institution

Share this abstract

Relevant publications

Book cover thumbnail image
Predicting the Admission Decision of a Participant...
by Yigit Ozsert, Gozde
   
Book cover thumbnail image
Development of New Models Using Machine Learning M...
by Akgol, Derman
   
Book cover thumbnail image
The Adaptation Process of a Resettled Community to... A Study of the Nubian Experience in Egypt
by Fahmi, Wael Salah
   
Book cover thumbnail image
Development of an Artificial Intelligence System f...
by Chand, Praneel
   
Book cover thumbnail image
Theoretical and Experimental Analysis of Dissipati...
by Latour, Massimo
   
Book cover thumbnail image
Optical Fiber Sensors for Residential Environments
by García-Olcina, Raimundo
   
Book cover thumbnail image
Calibration of Deterministic Parameters Reassessment of Offshore Platforms in the Arabian ...
by Zaghloul, Hassan
   
Book cover thumbnail image
How Passion Relates to Performance A Study of Consultant Civil Engineers
by Cadieux, Trevor J.