Indian Journal of Engineering & Materials Sciences Vol. 12, April 2005, pp. 158-164 Correlations for predicting detonation temperature of pure and mixed CNO and CHNO explosives M H Keshavarz Department of Chemistry, Malek-ashtar University of Technology, Shahin-shahr P.O. Box 83145/115, Islamic Republic of Iran Received 25 May 2004; accepted 10 January 2005 In this paper, detonation temperature of CNO and CHNO explosives is evaluated by the base of atomic composition and heat of formation. It is shown here how only atomic composition and condensed phase heat of formation of CNO and CHNO explosives are sufficient for reliable prediction of detonation temperature as compared to complicated computer codes. New correlations are introduced so that they can easily be applied for determining detonation temperature via specified different pathways of decomposition of explosives. Calculated detonation temperatures by this procedure for both pure and explosive formulations show good agreement with respect to measured and the BKWS-EOS predictions of detonation temperatures. IPC Code: C06B 25/00 The detonation parameters such as heat of detonation, detonation temperature, detonation velocity and detonation pressure are a variety of performance parameters for measuring the effectiveness of different explosives. When an explosive is initiated to detonation, a detonation wave has traversed through its medium so that the hot gases and solid residues left behind continue to exert pressure. Since detonation reaction of an explosive is extremely fast, the heat liberated by detonation will raise the temperature of gases, which will in turn cause them to expand and work on surroundings. Most of the work of an explosive in detonation is performed by the detonation reaction products. Typical detonation products of high explosives with the elements carbon, hydrogen, nitrogen and oxygen at high pressures (p~1-100 GPa) and temperatures (T~1000-5000 K) simultaneously are CO, N 2 , CO 2 , H 2 O, and solid carbon. Releasing a large amount of energy and complex chemical reactions are initiated to sustain the detonation process. The application of the hydrodynamic theory for calculating the detonation properties requires knowledge of the equation of state of the system that can accurately reflect the thermodynamic properties of multicomponent mixtures at several thousand Kelvin and hundreds of kbar, as well as at much lower temperatures and pressures obtained during expansion of the reaction products. Different computer codes such as BKW 1 and RUBY 2 and latter's offspring TIGER 3 , CHEQ 4 , and CHEETAH 5 assume all of the chemical equations for all possible species in the reaction product gases and solving these with thermo- chemical analogues. They can also estimate the isentropic expansion having the equilibrium energy and gas quantities along with the Rankine-Hugoniot jump equations. For example CHEETAH, a C version of the FORTRAN equilibrium code TIGER, is an equilibrium thermochemical code used to estimate detonation parameters for explosives, as well as parameters other conditions such as a constant volume explosion. The detonation parameters can usually be calculated by a computer code when the heat of formation and the density of the explosive substance are known and the equation of state (EOS) is assumed. There are several forms of EOSs such as Becker-Kistiakosky-Wilson (BKW) 6 , the Jacobs- Cowperthwaite-Zwisler (JCZ) 7,8 , Kihara-Hikita- Tanaka (KHT) 9 , Exp-6 10 and Lennard-Jones- Denvoshire (LJD) 11 . Of different EOSs, the BKW- EOS is used extensively to calculate detonation properties 1 . The BKWC-EOS 5 , BKWR-EOS 12 and BKWS-EOS 13 are three different parameterizations of the BKW-EOS so that BKWS-EOS is one of the best EOSs for predicting detonation temperatures. _________ E-mail: mhkir@yahoo.com; mhkeshavarz@mut-es.ac.ir