A Liner or a Thermal Insulating material is a substance of extremely low thermal conductivity. It helps to prevent or retard the loss of heat which takes place by convection, conduction and radiation. Rocket motor casings are generally made of metal, a composite material, or a combination of metal and composite materials. The combustion of a solid rocket propellant generates extreme conditions within the rocket motor casing and the temperatures can reach 2,760 C. (5,000 F.). In addition, the gases produced during propellant combustion typically contain high-energy particles that, under a turbulent environment, can erode the rocket motor insulation. If the propellant penetrates through the insulation and liner, the casing may melt, causing the rocket motor to fail. Hence during such operations, a heat-insulating layer protects the rocket motor casing from thermal effects and erosive effects of particle streams generated by combustion of the propellant. An experiment has been carried out in order to evaluate the Temperature, Mass flow rate and heat rates of hot gases through oxy-acetylene torch. The Purpose behind doing this experiment is to test the liner materials in rocket motor, by estimating the heat rate coming out of torch and temperature, by using mass flow rates of oxygen and acetylene gases. Heat flux generated from combustion of gases also gives us the idea of the temperature at which the liner materials can withstand. The experiment setup is divided into three modules i.e.a) Mass flow rate estimationb) Heat rate estimation c) Temperature estimation.The Mass flow rates of Oxygen and acetylene are estimated by Mass flow rate = (Mass of air(gas))/time; Heat Rate can be estimated as : mass flow rate ~* heat of combustion, where Heat of combustion = enthalpy of products= mcpdTΔH = M ~* h/3(T0 + Tn ) +2( T2 + T4 +..... ) - 4(T1 + T3 +......),h= (Tn - T0) and M=molecular weight.Temperature estimation can be done as: mac ~* ΔHac = (mac+ mO2) ~* m ~* cp ~* ΔTΔT = (Tx - Tamb ) ,Tx can be calculated from the above eqn for different ratios of 02 and acetylene flow rates. After attaining the experimental values of mass flow rates and temperature to be used, the torch is set to generate the amount of heat source. The heat flame or the combustion gases are directed normal to the specimen; it will be subjected to the burn-through stage. The erosion rate is determined by dividing the original thickness by the time to burn- through.
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