scholarly journals Investigation of the effect of ring-cavity on secondary-combustion and interior ballistic stabilization with low-temperature solid propellant in gas ejection

2021 ◽  
Vol 349 (2) ◽  
pp. 391-413
Author(s):  
Xiao-lei Hu ◽  
Jia-yi Guo ◽  
Chuan-bin Sun ◽  
Gui-gao Le
Author(s):  
Petr Mitrovich ◽  
◽  
Vladimir Malinin ◽  

The existing sources of the operating fluid used in aviation and rocket-space technology are analyzed. The disadvantages of inert gas cylinders used as a source of the operating fluid of the component supply system in jet engines are considered. An alternative to the gas pressure system is a low temperature solid propellant gas generator (LTGG) with a coolant. Controllable powdery components supply scheme of an air-breathing engine (ramjet) is proposed. The principle of operation of such a feeding scheme is described. To ensure the stability of the output characteristics of the LTGG, a valve system is used. The requirements for the gas source and combustion products (CP) involved in the operating process have been determined. The analysis of the existing methods of cooling the CP is carried out. It was revealed that the low-temperature solid-propellant gas generator with a powdery capacitance coolant meets the most fully the above requirements, the principle of operation, which is based on the heat transfer wave localization effect. Solid propellant with the following composition: 38 % AP + 38 % Octogen + 24 % SKI-NL is selected. The CP temperature, at a pressure in the combustion chamber of 6 MPa, is 1545 K, and the CP gas constant is 459.4 J / kg·K, the condensed phase is absent, and the water vapor content in the operating fluid does not exceed 1.6 %. The combustion of the proposed propellant produces a significant amount of combustible components – 60 % CO, 4 % H2, > 1 % CH4. The use of valves on cold gas ensures the reliability of the controlled supply system of powder components, and, accordingly, the entire engine. Based on the results of the work, conclusions were made about the correspondence of the obtained parameters of solid propellant and LTGG to all the requirements set.


2015 ◽  
Vol 645-646 ◽  
pp. 184-189 ◽  
Author(s):  
Cheng Bo Ru ◽  
Ying Hua Ye ◽  
Jian Bing Xu ◽  
Zhen You Zou ◽  
Ji Dai ◽  
...  

Considering the safety of the charge filled in the chambers and the operational reliability, a low temperature eutectic alloy bonding was preferred for the final assembling process of MEMS-based solid propellant microthrusters (SPM) array with top-side igniters. The optimum conditions of the alloy coating are the pH value of the solution is 0.5, the base metal layer is composed of Ti (60nm)/Cu (500nm) deposited by magnetron sputtering. The bonding process was conducted in an oven with air and the bonding temperature is 70°C. To predict the performance of bonding layer, the temperature distributions of eutectic alloy layer were simulated by ANSYS software when the chamber is full of high temperature reactants. The simulation results demonstrated the bonding strength wouldn’t cut down since the heat transfer induced by the combustion of charge. The assembled MEMS-SPM array was tested under constant voltage, the results indicated that the eutectic solder bonding procedure meet the requirements of the MEMS-SPM assembling.


RSC Advances ◽  
2015 ◽  
Vol 5 (79) ◽  
pp. 64478-64485 ◽  
Author(s):  
Abbas Tanver ◽  
Mu-Hua Huang ◽  
Yunjun Luo ◽  
Syed Khalid ◽  
Tariq Hussain

High energetic propellants with synergistic mechanical strength are the prerequisites for aerospace industry and missile technology; though glycidyl azide polymer (GAP) is a renowned and a promising energetic polymer which shows poor mechanical and low-temperature properties.


Author(s):  
P.P.K. Smith

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.


Author(s):  
S. Edith Taylor ◽  
Patrick Echlin ◽  
May McKoon ◽  
Thomas L. Hayes

Low temperature x-ray microanalysis (LTXM) of solid biological materials has been documented for Lemna minor L. root tips. This discussion will be limited to a demonstration of LTXM for measuring relative elemental distributions of P,S,Cl and K species within whole cells of tobacco leaves.Mature Wisconsin-38 tobacco was grown in the greenhouse at the University of California, Berkeley and picked daily from the mid-stalk position (leaf #9). The tissue was excised from the right of the mid rib and rapidly frozen in liquid nitrogen slush. It was then placed into an Amray biochamber and maintained at 103K. Fracture faces of the tissue were prepared and carbon-coated in the biochamber. The prepared sample was transferred from the biochamber to the Amray 1000A SEM equipped with a cold stage to maintain low temperatures at 103K. Analyses were performed using a tungsten source with accelerating voltages of 17.5 to 20 KV and beam currents from 1-2nA.


Sign in / Sign up

Export Citation Format

Share Document