Microwave-Supported Plasma Combustion Enhancement of Composite Solid Propellants Using Alkali Metal Dopants <br />

Two-photon laser-induced fluorescence in sodium-doped composite propellant flame

“…Taken together, the increase in sodium seems to be driven by an interplay between sodiumdopant and aluminum content. This complementary picture is consistent with the burning rate observations presented by Barkley et al 9 and in the early discussion in this dissertation.…”

“…Studies on the microwave-throttling of composite propellant formulations with the addition of sodium dopant have identified a complicated set of mechanisms with potential energy addition in the gas phase, the condensed phase of the bulk propellant, and the condensed-phase products present in metalized propellant formulations 9 . In the deposition to the gas-phase of these flames, the hypothesis is that the doping level of sodium is a significant driver in the amount of absorbed energy.…”

“….1 Modified WR430 test section in this experiment APPENDIX C. SIFT IMAGE REGISTRATION MATLAB CODE clear all; clc; close all Img_1 = Image_1(:,:,10); % One camera target Image Img_1_bs = bitshift(Img_1,2); Img_1_bgsub = medfilt2(Img_1_bs, [9,9]); % Image smooth Img_1_bi = imbinarize(Img_1_bgsub, 0.2); % image binarized bw = Img_1_bi; Img_2 = imread('register_4.tif', 3); % Another camera target image Img_2 = fliplr(Img_2); Img_2 = bitshift(Img_2, 6); Img_2 = medfilt2(Img_2, [5,5] figure; showMatchedFeatures(bw,Img_2_fl, inlierPtsOriginal,inlierPtsDistorted); title('Matched inlier points'); outputView = imref2d(size(bw)); Ir = imwarp(Img_2_fl,tform,'OutputView',outputView); figure; imshowpair(bw, Ir) save('Tform_1.mat', 'tform')…”

“…Energy can be deposited through dielectric absorption to high temperature aluminum oxide features (oxide smoke and oxide cap) within aluminum droplet diffusion flames. Condensed phase heating can also contribute to the burning rate enhancement through dielectric absorption mechanisms.In prior work, we have demonstrated the use of alkali metal doping for efficient, moderate-field-strength microwave energy deposition to the flame, which results in significant combustion enhancement9 . The mechanisms of microwave energy deposition in alkali-doped solid propellant enhancement are highlighted inFigure 2.9, reproduced from Barkley et al86 .…”

Experimental study on microwave ignition of ADN-based liquid propellant droplets doped with alumina nanoparticles

“…The directed input of microwave energy contributes to active control for enhancing the release of heat from the flame [20,21]. Barkley et al investigated the effects of NaNO 3 nanoparticles on the combustion of composite propellants by inducing flame-induced deposition of microwave energy at Na atomic formation sites [22]. The results revealed that a lower mixing ratio (3.5%) resulted in the formation of plasma within the propellant flame, increasing the combustion rate by 67%.…”