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An experimental investigation on heat transfer at various zones of the combustion chamber has been carried out using a non-circular inlet at the flame tube. With an aim to improve the turbulent level in flow, the non-circular section used here is an elliptical one. In addition to this, two rectangular tabs are placed at major axis of the ellipse to achieve an efficient mixing of fuel and air. Fuel used for combustion is kerosene while LPG gas is used for pre ignition. Fuel is fed to the chamber by gravity system and it has been atomized by two fish tank pumps. Ignition of the fuel is done by spark plug with a separate setup. The setup comprises of growler and CDI coil which are powered electrically. During the experiment, combustion has been initiated by allowing the air from blower to the chamber. The fuel is sprayed into the flame tube through fuel injector placed at a specified distance. After the proper mixing of fuel and air, the mixture is ignited by spark plug setup. Fuel tank has been calibrated for mass flow rate. The experiment has been carried out for different intervals of time and the heat transferred from the flame tube wall and chamber wall are measured using an infrared gun (ray gun) by pointing laser on the wall. The temperatures at different zones are measured. It is seen that the overall heat transfer at secondary zone is minimum when compared with the other zones for the same period of time. This indicates that if the fuel injector is placed before the secondary zone, then a maximum flame temperature can be obtained. This leads to an improvement in efficiency of the combustion chamber. [ABSTRACT FROM AUTHOR]

An experimental investigation on heat transfer at various zones of the combustion chamber has been carried out using a non-circular inlet at the flame tube. With an aim to improve the turbulent level in flow, the non-circular section used here is an elliptical one. In addition to this, two rectangular tabs are placed at major axis of the ellipse to achieve an efficient mixing of fuel and air. Fuel used for combustion is kerosene while LPG gas is used for pre ignition. Fuel is fed to the chamber by gravity system and it has been atomized by two fish tank pumps. Ignition of the fuel is done by spark plug with a separate setup. The setup comprises of growler and CDI coil which are powered electrically. During the experiment, combustion has been initiated by allowing the air from blower to the chamber. The fuel is sprayed into the flame tube through fuel injector placed at a specified distance. After the proper mixing of fuel and air, the mixture is ignited by spark plug setup. Fuel tank has been calibrated for mass flow rate. The experiment has been carried out for different intervals of time and the heat transferred from the flame tube wall and chamber wall are measured using an infrared gun (ray gun) by pointing laser on the wall. The temperatures at different zones are measured. It is seen that the overall heat transfer at secondary zone is minimum when compared with the other zones for the same period of time. This indicates that if the fuel injector is placed before the secondary zone, then a maximum flame temperature can be obtained. This leads to an improvement in efficiency of the combustion chamber. [ABSTRACT FROM AUTHOR]

This paper details the influence of geometry variation such as shape transition of the isolator from its entry to exit on overall performance of scramjet isolators. The experiments are conducted to assess the performance of two isolator geometries of circle to pentagon and circle to hexagon. The pseudo shock length is obtained for the two cases by observing the sudden pressure rise in pressure plots taken along the wall. It is found that the shock train length is shorter for circular to pentagon duct compared with the other duct. Hence, this duct is preferable in order to prevent inlet non-start induced by the pressure rise in the combustion chamber. [ABSTRACT FROM AUTHOR]