Space systems design (spacecraft, satellites, space stations and their equipment)
Hojat Ghasemi; Seyed Mohammadreza Mahmoudian; Noordin Qadiri Massoom; S. Rashad Rouholamini; Pouria Mikaniki; Asghar Azimi
Volume 16, Issue 1 , March 2023, , Pages 47-58
Abstract
The aim of the present research is to obtain the ability to use the cryogenic propellant engines on a laboratory scale. In this regard, it is necessary to build some experimental motors and investigate the their performance parameters. The liquid oxygen as a common oxidizer and ethanol as a green fuel ...
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The aim of the present research is to obtain the ability to use the cryogenic propellant engines on a laboratory scale. In this regard, it is necessary to build some experimental motors and investigate the their performance parameters. The liquid oxygen as a common oxidizer and ethanol as a green fuel have been selected as propellant components. The engine is designed to produce 400 kgf force at the nominal condition. The pintle type injector has been chosen in which liquid oxygen and fuel are flowed in the axial and radial directions, respectively. The combustion chamber has been protected against overheating by applying the regenerative cooling. However, the laboratory feature of the engine design has provided the using of water instead the cooling propellant. All main components of the engine such as injector, igniter, and flow controllers, are examined by the cold tests. A comprehensive test facility is designed and set up for hot fire tests in which the performance of almost all parameters can be evaluated. Fifteen fire tests have been performed. Maximum obtained pressure and evaluated combustion efficiency were about 75% of design values.
Hojat Ghassemi; Mohammad Nadafi – Pour Meibody; Keyvan Shaabani; Isa Asghari; Ebrahim Zanjirian
Volume 5, Issue 4 , January 2013, , Pages 19-28
Abstract
The application of the hydrogen peroxide as the oxidizer of a HTPB-based prototype hybrid motor is investigated in this paper. First of all, by studying the thermochemical characteristics of the propellant,operation range of different compositions is defined. A prototype hybrid motor is then designed ...
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The application of the hydrogen peroxide as the oxidizer of a HTPB-based prototype hybrid motor is investigated in this paper. First of all, by studying the thermochemical characteristics of the propellant,operation range of different compositions is defined. A prototype hybrid motor is then designed and manufactured, which is able to produce 10 kg propellant thrust. Conducting a special procedure available stabilized commercial hydrogen peroxide is processed and converted to a 90% density propellant which has less than 15 ppm tainting. A catalytic igniter is used in order to fire the motor. It was observed that the approach of employing the oxidizer to the catalyst bed is highly effective on the quality of the system performance. So, the injection quality of the oxidizer was investigated for different mass flow rates. The performance of the hybrid motor by HTTPB fuel is studied in a successful experimental test. The results of the test including the pressure and characteristic velocity are compared with the predicted theoretical simulations. Moreover, the performance specifications of the motor like the regression rate are determined and compared with the similar researches.
H. Ghasemmi; A. Barkhordar
Volume 5, Issue 1 , April 2012, , Pages 15-28
Abstract
Instantaneous grain geometry is one of the most affecting parameters on the performance of the solid rocket motors (SRMs). This paper presents the simulation of geometrically complicated solid propellant grain burnback using the level set method. The initial form of the grain is assumed in this method. ...
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Instantaneous grain geometry is one of the most affecting parameters on the performance of the solid rocket motors (SRMs). This paper presents the simulation of geometrically complicated solid propellant grain burnback using the level set method. The initial form of the grain is assumed in this method. Propagation of the grain boundaries in a velocity field is described using the Hamilton-Jacobi type equation. The solution of this equation in successive time steps gives the new burning boundaries of the grain. For this purpose, the initial geometry of grain is modeled in any CAD software. Then, the initial burning surfaces of grain are implicitly defined by the sign distance function and are used as the initial conditions of the level set equation. The geometrical characteristics of grain, such as burning surface area, port area, burning perimeter, and port volume are determined by Heaviside and Delta Dirac functions. The result of simulation is validated by an analytically predictable case, which shows excellent agreement. Burnback analysis is done for some practical grains including two cases that the test data were available. Using an unsteady zero dimension interior ballistic analysis, the resulting motor pressure curves are compared with the experimental data showing good agreement. The capability of the approach to handle the analyzing of problems, including non uniform burning velocity and arbitrary burnout configurations of grain are shown in examples.
