Journal of Hazardous Materials A136 (2006) 475–481 Computer code for the optimization of performance parameters of mixed explosive formulations H. Muthurajan a,∗ , R. Sivabalan b , M.B. Talawar b , S. Venugopalan b , B.R. Gandhe b a Armament Research and Development Establishment, Pashan, Pune 411 021, India b High Energy Materials Research Laboratory, Sutarwadi, Pune 411 021, India Received 23 October 2005; received in revised form 30 December 2005; accepted 19 January 2006 Available online 13 March 2006 Abstract LOTUSES is a novel computer code, which has been developed for the prediction of various thermodynamic properties such as heat of formation, heat of explosion, volume of explosion gaseous products and other related performance parameters. In this paper, we report LOTUSES (Version 1.4) code which has been utilized for the optimization of various high explosives in different combinations to obtain maximum possible velocity of detonation. LOTUSES (Version 1.4) code will vary the composition of mixed explosives automatically in the range of 1–100% and computes the oxygen balance as well as the velocity of detonation for various compositions in preset steps. Further, the code suggests the compositions for which least oxygen balance and the higher velocity of detonation could be achieved. Presently, the code can be applied for two component explosive compositions. The code has been validated with well-known explosives like, TNT, HNS, HNF, TATB, RDX, HMX, AN, DNA, CL-20 and TNAZ in different combinations. The new algorithm incorporated in LOTUSES (Version 1.4) enhances the efficiency and makes it a more powerful tool for the scientists/researches working in the field of high energy materials/hazardous materials. © 2006 Elsevier B.V. All rights reserved. Keywords: Mixed explosives; Velocity of detonation; Oxygen balance; Explosive formulations; Modelling; Hazardous materials 1. Introduction The study of energetic systems by theoretical methods has accelerated dramatically over the course of the last two decades and has proved considerable insight into the understanding of energetic materials [1–5]. The ability to predict the performance parameters of new explosive formulation is very much use- ful before one undertakes the laborious and expensive process of synthesising/formulating the same. Rigorous theoretical and mathematical approaches developed at present allow us to for- malize the knowledge of specialists in formulation of mixed explosive composition. Most explosive and propellant compo- sitions contain a mixture of components to have a maximum performance. Some of the components may not contribute to the heat liberated and may not even contain oxygen. These materi- als may however, contribute to the gaseous products and reduce ∗ Corresponding author. Tel.: +91 20 25886361; fax: +91 20 25893102. E-mail addresses: muthurajan h@rediffmail.com, muthurajan h@yahoo.com (H. Muthurajan). the actual temperatures obtained on detonation of the explosive or burning of the propellant. For example, the explosive amatol contains mixtures of ammonium nitrate and TNT. Ammonium nitrate has an oxygen balance of +20% and TNT has an oxygen balance of -74%, so it would appear that the mixture yielding an oxygen balance of zero would also result in the best explo- sive properties. In actual practice a mixture of 80% ammonium nitrate and 20% TNT by weight yields an oxygen balance of +1%, and shows an increase in strength of 30% over TNT. Computation to get maximum performance properties of mixed explosive composition by repeated iteration calls for tedious calculation. A new algorithm developed by authors is time saving as well as accurate for the prediction of performance parameters of mixed explosive composition and it is success- fully incorporated with LOTUSES code. LOTUSES also can predict the velocity of detonation, density, C–J pressure, heat of explosion, heat of formation, volume of explosion of gaseous products, etc. [6–10]. The new algorithm incorporated enhances its efficiency and allow theoretical screening of notional haz- ardous materials for identification of promising mixed explosive composition for additional study and elimination of weaker can- 0304-3894/$ – see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.jhazmat.2006.01.066