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Ak M.A.,Turkish Scientific and Technological Council | Ulas A.,Middle East Technical University | Sumer B.,Turkish Scientific and Technological Council | Yazici B.,Turkish Scientific and Technological Council | And 3 more authors.
Fuel | Year: 2011

This paper presents the hypergolic ignition test results of a potential environmentally friendly liquid propellant consisting of hydrogen peroxide oxidizer (with a concentration of 85%) and ethanolamine fuel for use in rocket engines. Open cup drop tests were conducted to study the effect of amount of metal salt catalyst in fuel and the initial temperatures of fuel and oxidizer on the ignition delay time. To test the hypergolic ignition of bipropellant formulation in a real rocket engine environment, a pressure-fed liquid propellant rocket engine (LPRE) was designed and developed. During the tests it was found that the amount of catalyst and the initial temperature of the fuel had a significant effect on the ignition delay of hypergolic bipropellant. However, the oxidizer temperature seemed to have almost no affect on the ignition delay. There was also significant difference between the ignition delay times from open cup tests and those from rocket engine static firings. © 2010 Elsevier Ltd. All rights reserved.

Ulas A.,Middle East Technical University | Cengiz F.,Turkish Scientific and Technological Council
Propellants, Explosives, Pyrotechnics | Year: 2011

In this paper, a study on the development of a numerical modeling of the detonation of C-H-N-O-based gaseous explosives is presented. In accordance with the numerical model, a FORTRAN computer code named GasPX has been developed to compute both the detonation point and the detonation properties on the basis of Chapman-Jouguet (C-J) theory. The determination of the detonation properties in GasPX is performed in chemical equilibrium and steady-state conditions. GasPX has two improvements over other thermodynamic equilibrium codes, which predict steady-state detonation properties of gaseous explosives. First, GasPX employs a nonlinear optimization code based on Generalized Reduced Gradient (GRG) algorithm to compute the equilibrium composition of the detonation products. This optimization code provides a higher level of robustness of the solutions and global optimum determination efficiency. Second, GasPX can calculate the solid carbon formation in the products for gaseous explosives with high carbon content. Detonation properties such as detonation pressure, detonation temperature, detonation energy, mole fractions of species at the detonation point, etc. have been calculated by GasPX for many gaseous explosives. The comparison between the results from this study and those of CEA code by NASA and the experimental studies in the literature are in good agreement. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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