Thermochemical Design of a Micro Liquid Monopropellant Rocket With Catalytic Reaction of Hydrogen Peroxide

2002 ◽  
Author(s):  
Dae Hoon Lee ◽  
Sejin Kwon ◽  
Jin Soo Hwang ◽  
Sang-Eon Park
Keyword(s):  
Hydrogen Peroxide ◽  
Thermodynamic Properties ◽  
Internal Surface ◽  
Decomposition Process ◽  
Reacting Flow ◽  
Reaction Products ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Thermochemical Process ◽  
Micro Propulsion

A theoretical and experimental investigation on a design of catalytic reactor of submilimeter scale to be used as a micro propulsion device is described. A micro reactor was fabricated on an aluminum plate and catalyst was prepared on the anodized internal surface of the reactor. The reactor has a height of 1mm and width of 10mm. The height of the reactor is the major constraint when a prototype device is to be fabricated on a wafer by MEMS processing. Thermodynamic properties of product gases from the decomposition process of hydrogen peroxide in contact with perovskite based redox cycling catalyst were measured. A theoretical model was developed to predict the heat and gaseous mass generated from the decomposition process of hydrogen peroxide by using asymptotic approximation of reacting flow in 1-D channel with height of 1mm or less in order to approximate the actual operating condition of propulsion device on a chip. The measured heat transfer coefficients and thermodynamic properties were used in the calculation. As the monopropellant decomposes into water and oxygen, the reaction products are heated. The enhanced heat loss due to the small size of the chamber, however, adversely affected the thermochemical process of decomposition.

A Transient Calorimeter Technique for Determining Regional Heat Transfer Coefficients in the Three-Temperature Flowfield at a Turbine Airfoil Leading Edge

2005 ◽  
Author(s):  
Scott R. Nowlin ◽  
David R. H. Gillespie ◽  
Peter T. Ireland ◽  
Ralf Knoche ◽  
T. Robert Kingston
Keyword(s):  
Heat Transfer ◽  
Film Cooling ◽  
Internal Flow ◽  
Leading Edge ◽  
Internal Surface ◽  
Reynolds Numbers ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Novel Method ◽  
Exposed Surface Area

In this paper, the authors develop a novel method of obtaining regionally-averaged heat transfer coefficients in flowfields characterized by three temperatures using the well-known transient calorimeter technique. The technique is used to determine heat transfer in aluminum models of idealized turbine blade leading edges cooled through internal surface impingement, film cooling feed passages, and external convective film cooling. The external surface is subject to a stagnating mainstream crossflow. Importantly, the contributions to heating from the external flow and cooling from the internal flow can be separately resolved solely by heating the internal flow. Results for a basic showerhead geometry and an advanced intersecting-passage cooling configuration are presented for a range of internal and external Reynolds numbers. The intersecting-passage model shows little improvement in heat transfer coefficient over the showerhead for the flow conditions tested; however, the total cooling carried out is improved by the increase in exposed surface area. The technique’s uncertainties are fully assessed.

scholarly journals The Development and Application of Improved Combustor Wall Cooling Techniques

1980 ◽  
Author(s):  
A. B. Wassell ◽  
J. K. Bhangu
Keyword(s):  
Heat Transfer ◽  
Internal Surface ◽  
Transfer Coefficients ◽  
Internal Surface Area ◽  
Impingement Cooling ◽  
Cooling Flow ◽  
Heat Transfer Coefficients ◽  
Impingement Heat Transfer ◽  
Low Emission ◽  
Combustor Liner

The continuing emphasis over the past few years on the development of lower sfc, long on-wing life and low emission engines for commercial transportation has put a premium on combustor liner cooling techniques employing less cooling flow. Rolls-Royce pioneered the fully machined ring and impingement cooling concepts which formed the basis for the RB211 combustor design. Further improvement of the impingement cooling technique has led to the development of a laminated, psuedo-transpiration material. It exploits the high impingement heat transfer coefficients and provides an extended internal surface area for heat transfer. Rolls-Royce has developed this material primarily for combustor applications. A major milestone has now been achieved with the certification by the CAA of a Spey combustor variant incorporating this material for limited release for commercial operations. These combustors are now entering service in the BAe1-11 with a number of UK airlines.

scholarly journals Measurement of heat transfer coefficients in stirred single-use bioreactors by the decay of hydrogen peroxide

2017 ◽  
Vol 17 (12) ◽  
pp. 1234-1243 ◽  
Author(s):  
Matthias Müller ◽  
Wolfram Meusel ◽  
Ute Husemann ◽  
Gerhard Greller ◽  
Matthias Kraume
Keyword(s):  
Heat Transfer ◽  
Hydrogen Peroxide ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Single Use

scholarly journals Quantifying Heat Transfer Characteristics of the Kroll Reactor in Titanium Sponge Production

2021 ◽  
Vol 9 ◽  
Author(s):  
Wenhao Wang ◽  
Fuzhong Wu
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
External Surface ◽  
Titanium Sponge ◽  
Internal Surface ◽  
Heat Transfer Characteristics ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Transfer Characteristics ◽  
Cooling Air

Various reactors with different sizes have been widely used for the production of titanium sponge in the Kroll process. But the further commercialization of the forced heat transfer design of the Kroll reactor is limited by lack of standard parameter to evaluate its convective heat transfer characteristics. This work proposes to evaluate and compare the Kroll reactor with the dimensionless Nusselt number. The results shown that the heat transfer coefficients for both surfaces increase with the volume flow rate of cooling air for each dimensionless temperature, and the heat transfer coefficients of the external surface of the reactor are higher than that of the internal surface of the heater. And new correlations regarding the Nusselt number between the cooling air and the external surface of the reactor or the internal surface of the heater are obtained based on experimental data, while the characteristics of the cooling air, equipment and operation parameters are considered.

Exergy and sensibility analysis of each individual effect in a kraft multiple effect evaporator

TAPPI Journal ◽  
2019 ◽  
Vol 18 (10) ◽  
pp. 607-618
Author(s):  
JÉSSICA MOREIRA ◽  
BRUNO LACERDA DE OLIVEIRA CAMPOS ◽  
ESLY FERREIRA DA COSTA JUNIOR ◽  
ANDRÉA OLIVEIRA SOUZA DA COSTA
Keyword(s):  
Optimization Problem ◽  
Real Data ◽  
Kraft Pulping ◽  
Steam Temperature ◽  
Input Flow ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Multiple Effect ◽  
Sensibility Analysis ◽  
Exergetic Analysis

The multiple effect evaporator (MEE) is an energy intensive step in the kraft pulping process. The exergetic analysis can be useful for locating irreversibilities in the process and pointing out which equipment is less efficient, and it could also be the object of optimization studies. In the present work, each evaporator of a real kraft system has been individually described using mass balance and thermodynamics principles (the first and the second laws). Real data from a kraft MEE were collected from a Brazilian plant and were used for the estimation of heat transfer coefficients in a nonlinear optimization problem, as well as for the validation of the model. An exergetic analysis was made for each effect individually, which resulted in effects 1A and 1B being the least efficient, and therefore having the greatest potential for improvement. A sensibility analysis was also performed, showing that steam temperature and liquor input flow rate are sensible parameters.

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