scholarly journals Determination of the Hall Thruster Operating Regimes

2002 ◽  
Author(s):  
L. Dorf ◽  
V. Semenov ◽  
Y. Raitses ◽  
N.J. Fisch
Keyword(s):  
Hall Thruster ◽  
Operating Regimes

scholarly journals Background Pressure Effects on the Performance of a 20 kW Magnetically Shielded Hall Thruster Operating in Various Configurations

Aerospace ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 69
Author(s):  
Antonio Piragino ◽  
Farbod Faraji ◽  
Maryam Reza ◽  
Eugenio Ferrato ◽  
Annalisa Piraino ◽  
...  
Keyword(s):  
Mass Flow ◽  
Discharge Current ◽  
Pressure Effects ◽  
Hall Thruster ◽  
Physical Processes ◽  
Linear Behavior ◽  
Mass Flow Rates ◽  
Anode Mass ◽  
Lower Background ◽  
Operating Regimes

The paper reports the characterization results of a 20 kW-class magnetically shielded Hall thruster in three different configurations and operating with a centrally mounted cathode. The characterization was carried out at two different pumping speeds in SITAEL’s IV10 vacuum chamber, resulting in two different background pressure levels for each tested operating point. A linear behavior of discharge current and thrust values versus the anode mass flow rate was noticed for both pumping speeds levels and for all the three configurations. In addition, the thrust and discharge current values were always found to be lower at lower background pressure levels. From the performance levels, a preliminary estimate of the ingested mass flow rates was performed, and the values were then compared to a recently developed background flow model. The results suggested that, for this thruster and in the tested operating regimes, the change in performance due to background pressure could be ascribed not only to the ingestion of external mass flow coming from the chamber but also to other physical processes caused by the flux of residual background neutrals.

Steady State Detection in Industrial Gas Turbines for Condition Monitoring and Diagnostics Applications

2014 ◽  
Author(s):  
Cesar Celis ◽  
Érica Xavier ◽  
Tairo Teixeira ◽  
Gustavo R. S. Pinto
Keyword(s):  
Steady State ◽  
Condition Monitoring ◽  
Gas Turbines ◽  
Signal Analysis ◽  
Operating Regime ◽  
State Detection ◽  
Industrial Gas Turbines ◽  
Monitoring And Diagnostics ◽  
Operating Regimes

This work describes the development and implementation of a signal analysis module which allows the reliable detection of operating regimes in industrial gas turbines. Its use is intended for steady state-based condition monitoring and diagnostics systems. This type of systems requires the determination of the operating regime of the equipment, in this particular case, of the industrial gas turbine. After a brief introduction the context in which the signal analysis module is developed is highlighted. Next the state of the art of the different methodologies used for steady state detection in equipment is summarized. A detailed description of the signal analysis module developed, including its different sub systems and the main hypotheses considered during its development, is shown to follow. Finally the main results obtained through the use of the module developed are presented and discussed. The results obtained emphasize the adequacy of this type of procedures for the determination of operating regimes in industrial gas turbines.

THE PROBLEM OF IDENTIFICATION OF HYDRAULIC RESISTANCE COEFFICIENTS IN MAKISTRAL GAS PIPELINE

2021 ◽  
pp. 6-11
Author(s):  
G. Gasymov
Keyword(s):  
Hydraulic Resistance ◽  
Group Identification ◽  
Numerical Approach ◽  
Transportation Systems ◽  
Gas Pipeline ◽  
Closed Loops ◽  
Hydraulic Network ◽  
Resistance Coefficients ◽  
Operating Regimes

A numerical approach, based on obtaining design formulas for the determination of hydraulic resistance coefficients of sites in pipeline transportation systems in the presence of the results of observations over a gas pipeline operating regimes, is proposed. The representation of the hydraulic network in the form of a directed graph allows to essentially reduce the number of equations in the system down to the number of closed loops. In the software implementation of the method described, for the solution of practical problems, group identification of the hydraulic resistance coefficients is provided for every eventuality.

scholarly journals An Analytical Method for the Determination of Temperature Distribution in Short Journal Bearing Oil Film

Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 539
Author(s):  
Nebojsa Nikolic ◽  
Zivota Antonic ◽  
Jovan Doric ◽  
Dragan Ruzic ◽  
Stjepan Galambos ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Oil Film ◽  
Symmetric Geometry ◽  
Experimental Values ◽  
Operating Regimes ◽  
Level Of Agreement

The aim of this paper is to derive an equation for the temperature distribution in journal bearing oil film, in order to predict the thermal load of a bearing. This is very important for the prevention of critical regimes in a bearing operation. To achieve the goal, a partial differential equation of the temperature field was first derived, starting from the energy equation coupled with the Reynolds equation of hydrodynamic lubrication for a short bearing of symmetric geometry. Then, by solving the equation analytically, the function of temperature distribution in the bearing oil film has been obtained. The solution is applied to the journal bearing, for which the experimental data are available in the references. Finally, the obtained results have been compared to the corresponding experimental values for two operating regimes, and a good level of agreement was achieved.

Experimental Determination of Kinetic Parameters for the Removal of Ethylacetate and Xylene in a Biofilter

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Saravanan Viswanathan ◽  
Manivasagan Rajasimman ◽  
Rajamohan Natarajan
Keyword(s):  
Ethyl Acetate ◽  
Gas Flow ◽  
Treatment Plant ◽  
Inlet Concentration ◽  
Process Variables ◽  
Flow Rates ◽  
Maximum Elimination Capacity ◽  
Operating Regimes ◽  
Industry Wastewater

Abstract The biofilter packed with pressmud and inoculated with activated sludge obtained from pharmaceutical industry wastewater treatment plant was employed for the removal of ethyl acetate and xylene in this study. The effect of process variables like gas flow rates (0.03, 0.06, 0.09 and 0.12 m3 h-1), inlet concentration of ethyl acetate (1.75, 3.0, 7.0 and 10.5 g.m-3) and xylene (0.2, 0.4, 0.6 and 1.2. g.m-3) on the performance of biofilters was validated. The removal efficiency exceeded 97% for ethyl acetate at inlet concentrations up to 3.0 g.m-3 and 95% for xylene at inlet concentrations up to 0.4 g m-3. The maximum elimination capacity of 165 g m-3 h-1 and 66 g m-3 h-1 for the mixture of ethyl acetate and xylene were obtained. A steady state mathematical model was tested and proved to adequately describe the experimental results at the two operating regimes for both ethyl acetate and xylene.

Risk-based Methodology for the Determination of Hall Thruster Performance Specifications

2021 ◽  
Author(s):  
Jason D. Frieman ◽  
Jon Mackey ◽  
Hani Kamhawi ◽  
Peter Y. Peterson ◽  
Richard R. Hofer
Keyword(s):  
Hall Thruster ◽  
Performance Specifications

Determination of the parameters of an axial pico-hydroturbine for various operating regimes

2021 ◽  
Vol 28 (4) ◽  
pp. 599-602
Author(s):  
S. I. Shtork ◽  
I. V. Litvinov ◽  
E. Yu. Gorelikov ◽  
D. A. Suslov
Keyword(s):  
Operating Regimes

scholarly journals In the Lab: Research and Development in the Field of (Renewable) Gas Processing Technology at DBI Group

2021 ◽  
Author(s):  
Stephan Anger
Keyword(s):  
Mathematical Models ◽  
Large Scale ◽  
Process Development ◽  
Gas Treatment ◽  
Gas Processing ◽  
Processing Plants ◽  
Important Design ◽  
Operating Regimes ◽  
Complete Process

DBI Group’s field of activity covers the complete process development of chemical processes, starting with the process balancing and testing of catalysts including the determination of catalyst-specific reaction kinetics, up to lifetime investigations, ageing tests and other reaction engineering investigations. With the data obtained, complex mathematical models can be generated which can be used for the design of reactors or the optimisation of operating regimes. In addition, the company also applies its know-how in the field of mathematical models in application-oriented simulations of thermal processing plants, heat exchangers and gas treatment plants. On the basis of these models, it designs demonstration plants which provide important design fundamentals and technical-scientific correlations for large-scale applications.

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