Technical Papers and Presentations

In previous work, a two-dimensional (2D) model was carried out to simulate the phononic band structure of a phononic crystal with square lattice structure, but this model did not account for the out-of-plane phonon dispersions [1]. In fact, for 2D films used for coating materials, it is ... Read More

Electrical Discharge Machining (EDM) is a non-conventional process used for machining electrically conducting materials. In die sink-EDM, sparks are generated between tool and workpiece resulting in heating of both electrode surfaces and creating a melt pool of metal which leads to ... Read More

Pressure-drop experiments were conducted for the turbulent, compressible flow of air in a small, slender tube, and modeled with COMSOL heat transfer module, and analytically. A scalar integration variable is introduced which integrates the mass velocity [kg/m²s] over the inlet area ... Read More

“NASA\'s Advanced Exploration Systems (AES) program is pioneering new approaches for rapidly developing prototype systems, demonstrating key capabilities, and validating operational concepts for future human missions beyond Earth orbit” [1]. Under the new Atmosphere Revitalization ... Read More

Composite repairs involve applying a prescribed heat flux which must be adjusted to account for heat losses. These losses must be estimated. Parameter estimation requires a knowledge of sensitivities. This is often done using finite differences. As shown in the figure, substantial errors ... Read More

The technique of water calorimetry for primary-standard dosimetry of radiotherapy-level ionizing radiation is well established at national metrology institutes around the world, where such a direct realization of absorbed dose establishes the basis for calibrating instruments used for ... Read More

This paper presents thermo-mechanical models for predicting the strength of polymer laminates loaded in tension or compression exposed to one-sided radiant heating by fire. The first part is the fire simulation where the FDS model is utilized. The FDS model generates a solution of ... Read More

All spacecraft systems must be minimized with respect to mass, power, and volume. Here, we focus on current efforts to improve system efficiency and reliability for water separation systems to be used on crewed vehicles. These development efforts combine sub-scale systems testing and ... Read More

The Oak Ridge National Laboratory (ORNL) is developing technology to re-establish the capability to produce plutonium-238 for the National Aeronautics and Space Administration (NASA) as a power source material for powering vehicles while in deep-space. The High Flux Isotope Reactor ... Read More

Laser percussion drilling is widely used in the aerospace industry to produce cooling holes in jet engine components. This process is a thermal, contact-free process which involves firing a sequence of focused optical pulses onto a target material [1-4]. During each optical pulse, the ... Read More