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Full-Text Articles in Engineering
Numerical Investigation Of Pyrolysis Gas Blowing Pattern And Thermal Response Using Orthotropic Charring Ablative Material, Haoyue Weng, Alexandre Martin
Numerical Investigation Of Pyrolysis Gas Blowing Pattern And Thermal Response Using Orthotropic Charring Ablative Material, Haoyue Weng, Alexandre Martin
Mechanical Engineering Faculty Publications
An orthotropic material model is implemented in a three-dimensional material response code, and numerically studied for charring ablative material. Model comparison is performed using an iso-Q sample geometry. The comparison is presented using pyrolysis gas streamlines and time series of temperature at selected virtual thermocouples. Results show that orthotropic permeability affects both pyrolysis gas flow and thermal response, but orthotropic thermal conductivity essentially changes the thermal performance of the material. The effect of orthotropic properties may have practical use such that the material performance can be manipulated by altering the angle of orthotropic orientation.
Numerical Study Of Spallation Phenomenon In An Arc-Jet Environment, Raghava Davuluri, Alexandre Martin
Numerical Study Of Spallation Phenomenon In An Arc-Jet Environment, Raghava Davuluri, Alexandre Martin
Mechanical Engineering Faculty Publications
The spallation phenomenon might affect the aerodynamic heating rates of re-entry vehicles. To investigate spallation effects, a code is developed to compute the dynamics of spalled particles. The code uses a finite-rate chemistry model to study the chemical interactions of the particles with the flow field. The spallation code is one-way coupled to a CFD solver that models the hypersonic flow field around an ablative sample. Spalled particles behavior is numerically studied for argon and air flow field. The chemistry model is compared with that of Park's model which complies with oxidation and sublimation and shows disagreement for nitridation.
Experimental And Numerical Study Of Carbon Fiber Oxidation, Francesco Panerai, Nagi N. Mansour, Jean Lachaud, Alexandre Martin
Experimental And Numerical Study Of Carbon Fiber Oxidation, Francesco Panerai, Nagi N. Mansour, Jean Lachaud, Alexandre Martin
Mechanical Engineering Faculty Publications
The oxidation at high Knudsen number of FiberForm® , the matrix material of NASA's Phenolic Impregnated Carbon Ablator, is investigated both experimentally and numerically. The experimental setup consists of a quartz tube through a clamshell heater. Mass loss and recession of carbon preform samples are measured at temperatures between 700 and 1300 K and pressures around 2000 Pa. A volume average fiber-scale oxidation model is used to model the setup and extract the effective reactivity of the material. New values for carbon fiber reactivity are suggested and discussed.