Revised 3 April 2006 Defence Science Journal, Vol. 57, No. 2, March 2007. pp. 2007, DESIDOC 223 SHORT COMMUNICATION Estimation of Heat Loss in a Closed Vessel B.A. Parate and C.M. Kulkarni Armament Research and Development Establishment, Pune-411 021 ABSTRACT Power cartridges are designed and developed for use in military aircraft in association with High Energy Materials Research Laboratory, Pune. During development, the cartridge is fired in a closed vessel to generate basic design parameters. When the cartridge is fired, the heat is lost to the walls of the vessel due to conduction, convection, radiation, and to some extent, by expansion of the vessel. An attempt has been made to estimate the heat loss from the vessel and the surrounding. The aim of this study was to lay down the technical results theoretically and their validation through experiments. Keywords: Closed vessel, heat transfer, heat loss, heat generation NOMENCLATURE A Surface area of the vessel b Co-volume of gas C Charge weight of propellant C v Specific heat at constant volume C p Specific heat at constant pressure C Mean molar heat capacities of gaseous products d Internal dia of vessel F Force constant of propellant h Overall heat transfer coefficient H Heat loss by propellant K Thermal conductivity l Length of closed vessel M Molecular weight m Mass of gaseous products n Number of moles of gas per unit mass P Maximum pressure obtained from P- t curve, when propellant is burned inside the closed vessel p Absolute pressure of gas Q Amount of heat generated by propellant R Gas constant for products of combustion T Temperature of propellant gas T a Ambient temperature T e Adiabatic flame temperature of propellant t Time when propellant burns T Temperature difference