Nitrogen Catalytic Recombination on Copper Oxide in Tertiary Gas Mixtures

Abstract

PrefaceThis master thesis represents the work that I have conducted at KAIST (Republic of Korea) from July 2013 until December 2013 and August 2014 until March 2015. During these period I have studied the field of aerothermodynamics, learned the necessary steps to conduct experiments individually, explored and studied various numerical programs to fulfill the goal of this research. This thesis is the final step in the journey to acquire the degree of Master of Science in Aerospace Engineering at Delft University of Technology.This report consists of three main parts. One part discusses the shock tube and the fabrication of heat transfer gauges. The second part introduces the numerical programs which are used to simulate the conditions inside the shock tube and around the model, whereas the third part covers the theory regarding heat flux and catalycity. These three parts together form a chain of required steps to acquire the desired results for this thesis.

Robust reconstruction of the catalytic properties of thermal protection materials from sparse high-enthalpy facility experimental data

“…While this is a conservative practice, there is compelling evidence that the actual surface of copper calorimeters is not fully catalytic, owing to the rapid oxidation of copper upon exposure to plasma. Numerous studies have been dedicated to characterize the catalytic properties of copper and its surface oxides (CuO and Cu 2 O) [10,13,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37]. In a second step, hot wall measurements are performed on the TPS material sample in order to determine its catalytic property γ, for a known test condition determined through the rebuilding of cold-wall measurements.…”

“…Even for well-characterized facilities, the determination of catalytic properties is affected by the noise present in the experimental data. The quantification of uncertainties in high-enthalpy experiments has previously been studied in the literature [13,14,15,16]. In particular, in our previous work [16], we evaluated the uncertainties on catalytic properties by coupling a deterministic catalytic property estimation with a Polynomial Chaos (PC) expansion method.…”

Radical probe system for in situ measurements of radical densities of hydrogen, oxygen, and nitrogen

“…For oxygen radicals, recombination coefficient on copper surface is 0.17 [30] and for stainless-steel surface is 0.07 [31]. Lastly, recombination coefficient for nitrogen radicals on copper surface is 0.068 [32] [33] and on stainless-steel surface is 0.002 [33]. There is discrepancy in academia regarding recombination coefficients' values, however, tabulated values used ( see table 4.1 ) to determine radical density are chosen closest to HARP chamber conditions.…”

Extension of the Frozen Sonic Flow Method to Mixtures of Polyatomic Gases

“…As in the absence of experimental data (no information available for the specific gas mixtures considered in the present work), the use of models is the only possible alternative, here the values of the constant k w for each gas mixture are determined using the formula based on the Maxwellian velocity distribution. Though this formula does not take into account concentration gradients due to catalysis, it has enjoyed a widespread use in the literature because it aligns with Goulard's main assumption of a frozen boundary layer (Goulard [30]; Cheung et al [35,36]):…”