scholarly journals Approach to solution of tank with hydrogen peroxide pressurization by its decomposition products

2021 ◽  
Vol 27 (5) ◽  
pp. 3-10
Author(s):  
M.V. Andriievskyi ◽  
◽  
Y.O. Mitikov ◽  
◽  
Keyword(s):  
Hydrogen Peroxide ◽  
High Temperature ◽  
Theoretical Calculations ◽  
Variable Mass ◽  
Gas Generator ◽  
Thermodynamic Relation ◽  
Engine Operation ◽  
Decomposition Products ◽  
System Parameters ◽  
Pressurization System

Aim. To find and confirm the possibility of hydrogen peroxide tank pressurization using high-temperature pressurization gas (~1100К) with a high percentage of steam (up to 70%) without its losses. Research methods. Mathematical modeling of pressurization system parameters with the theory of mass transfer and thermodynamic of variable mass bodies have been used. Results. The conducted research allowed us to find and confirm the possibility of using a new pressurization method with additional sources of heat and elaborate recommendations for its appliance during pressurization time. Scientific novelty. The main processes have been determined, which prevent implementation of the efficient high-temperature pressurization system of the tank with the hydrogen peroxide using peroxide decomposition products. The main obstacle is the volume condensation of vapor in the free volume of the tank when heat exchange processes with boundary surfaces take place. For the first time, by means of theoretical calculations, the expediency and rationality of using the additional sources of heat such as high-temperature combustion product of solid-fuel gas generator based on sodium azide have been proved. Using of this additional source for the first 30 seconds of engine operation has been proved. Practical value. Methodology of pressurization system parameters’ calculation was supplemented with discovered thermodynamic relation, which allowed us to calculate the amount of vapor and take some measures to eliminate the condensation. Results of the research allowed the designation of the pressurization system for the highly concentrated hydrogen peroxide tank with a high value of length to diameter relation with its high-temperature decomposition products.

Diffusivity, Solubility and Speciation of Sulphur in Silicate Melts

2006 ◽  
Vol 46 ◽  
pp. 93-97 ◽  
Author(s):  
J. Stelling ◽  
Harald Behrens ◽  
Joachim Deubener ◽  
Stefan Mangold ◽  
Joerg Goettlicher
Keyword(s):  
High Temperature ◽  
Electron Microprobe ◽  
Industrial Production ◽  
Silicate Melts ◽  
Viscosity Data ◽  
Decomposition Products ◽  
X Ray ◽  
Diffusion Couple Technique ◽  
X Ray Absorption ◽  
Diffusion Profiles

Diffusion and solubility of sulphur have important effects on the degassing of silicate melts. Both properties are closely related to the structural incorporation of sulphur in the melt. Depending on the oxygen fugacity, sulphur can be present as sulphide (S2-), sulphite (S4+) or sulphate (S6+). Sulphates play an important role in the industrial production of glasses especially in the fining process. The decomposition products of sulphate amass in bubbles which ascend and homogenize the melt. Structural incorporation of sulphur in glasses is studied by XANES (X-ray Absorption Near Edge Spectroscopy). Diffusion of sulphur is investigated in simple silicate systems using the diffusion couple technique. First diffusion profiles were measured in sodium trisilicate glasses by electron microprobe. The results indicate that sulphur diffusivity in high temperature melts is close to the Eyring diffusivity calculated from viscosity data.

Failure Analysis of Engine Valves and its Performance Evaluation under Various Titanium Based Composite Coatings Using FE Analysis

2021 ◽  
Vol 903 ◽  
pp. 79-89
Author(s):  
R. Sundara Rao ◽  
K. Hemachandra Reddy ◽  
Ch.R. Vikram Kumar
Keyword(s):  
Finite Element ◽  
High Temperature ◽  
Combustion Engine ◽  
Mechanical Load ◽  
Composite Coatings ◽  
Surface Hardness ◽  
Engine Operation ◽  
Engine Valve ◽  
Simulation Results ◽  
Two Wheeler

In an internal combustion engine poppet valve is the crucial component which often opens and closes, thereby regulating gas flow in an engine cylinder. During engine operation, the valve is exposed to high temperature gases (thermal load) along with spring and cam loads (mechanical load). Due to high temperatures and fatigue loads, the valves are subjected to metallurgical changes and leads to failure. In order to resist these extreme conditions of high temperature and mechanical loads, the engine valve should possess special properties such as high surface hardness, a good amount of thermal conductivity, and fatigue strength. In this work, the reasons for the failure of two wheeler engine valve were evaluated and found that failure takes place due to change in the chemical composition mainly due to thermal diffusion at the interfaces. Thermal barrier coatings on the valve surface arrest the temperature load and increase its life. In this work, the performance of various titanium based composite coatings, i.e., TiN, TiC, TiC-Al2O3, TiCN, TiAlN, TiN- Al2O3, DLC, and uncoated valves of two wheeler engine was simulated using Finite Element Analysis. The simulation results indicated that coated valves have less thermal and fatigue loading and have more life than the uncoated valve. The Finite element simulation results of both coated and uncoated valves are presented and analyzed in this paper.

scholarly journals Effect of the High Temperature Resistant Nano-Coolant on Automotive Engine Operation

2019 ◽  
Vol 5 (1) ◽  
pp. 1
Author(s):  
Xin Sha ◽  
Lu Ruirui ◽  
He Yan ◽  
Xu Changming ◽  
Luo Yi
Keyword(s):  
High Temperature ◽  
Engine Operation ◽  
Automotive Engine

Monopropellant-Driven Free Piston Hydraulic Pump for Mobile Robotic Systems

2004 ◽  
Vol 126 (1) ◽  
pp. 75-81 ◽  
Author(s):  
Timothy G. McGee ◽  
Justin W. Raade ◽  
H. Kazerooni
Keyword(s):  
Hydrogen Peroxide ◽  
High Temperature ◽  
Thermodynamic Analysis ◽  
Flow Rate ◽  
Power Supply ◽  
Robotic Systems ◽  
Hydraulic Fluid ◽  
Hydraulic Pump ◽  
Free Piston

The authors present a novel power supply for mobile robotic systems. A monopropellant (e.g., hydrogen peroxide) decomposes into high temperature gases, which drive a free piston hydraulic pump (FPHP). The elimination of fuel/oxidizer mixing allows the design of simple, lightweight systems capable of operation in oxygen free environments. A thermodynamic analysis has been performed, and an experimental FPHP has been built and tested. The prototype successfully pumped hydraulic fluid, although the flow rate was limited by the off-the-shelf components used.

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