Experimental data of the continuous evolution of fluid flow characteristics in a dump combustor is very useful and essential for better and optimum designs of gas turbine combustors and ramjet engines. Unfortunately, ...Experimental data of the continuous evolution of fluid flow characteristics in a dump combustor is very useful and essential for better and optimum designs of gas turbine combustors and ramjet engines. Unfortunately, experimental techniques such as 2D and/or 3D LDV （Laser Doppler Velocimetry） measurements provide only limited discrete information at given points; especially, for the cases of complex flows such as dump combustor swirling flows. For this type of flows, usual numerical interpolating schemes appear to be unsuitable. Recently, neural networks have emerged as viable means of expanding a finite data set of experimental measurements to enhance better understanding of a particular complex phenomenon. This study showed that generalized feed forward network is suitable for the prediction of turbulent swirling flow characteristics in a model dump combustor. These techniques are proposed for optimum designs of dump combustors and ramjet engines.展开更多
This paper repotts an experimental investigation of the flow field inside a low aspect ratio dump combustor.The length of the combustor studied was less than the reattachment length for the separated flow.The exit of ...This paper repotts an experimental investigation of the flow field inside a low aspect ratio dump combustor.The length of the combustor studied was less than the reattachment length for the separated flow.The exit of the combustor is tapered which supports the flow reversal from the exit section.The flow field behaviour in the combustor is evaluated from pressure and velocity measurement studies.The velocity,stream function and pressure distribution inside the combustor are used to elucidate the presence of recircu lation and flow reversal from the exit section of the combustor for different Reynolds numbers.A small variation in Ums velocity was observed in axial direction while in the radial direction it was quite high.Two recirculation zones are recognized and the strength of the recirculation was seen to increase with flow Reynolds number.The turbulence intensity in the recirculation and shear layer zone was seen to be higher than the potential core.展开更多
文摘Experimental data of the continuous evolution of fluid flow characteristics in a dump combustor is very useful and essential for better and optimum designs of gas turbine combustors and ramjet engines. Unfortunately, experimental techniques such as 2D and/or 3D LDV （Laser Doppler Velocimetry） measurements provide only limited discrete information at given points; especially, for the cases of complex flows such as dump combustor swirling flows. For this type of flows, usual numerical interpolating schemes appear to be unsuitable. Recently, neural networks have emerged as viable means of expanding a finite data set of experimental measurements to enhance better understanding of a particular complex phenomenon. This study showed that generalized feed forward network is suitable for the prediction of turbulent swirling flow characteristics in a model dump combustor. These techniques are proposed for optimum designs of dump combustors and ramjet engines.
基金This project is sponsored by ISRO and Space Technology Cell at Indian Institute of Technology,Kanpur.Mr.N.K.Gupta of LPSC is the project coordinator at ISRO。
文摘This paper repotts an experimental investigation of the flow field inside a low aspect ratio dump combustor.The length of the combustor studied was less than the reattachment length for the separated flow.The exit of the combustor is tapered which supports the flow reversal from the exit section.The flow field behaviour in the combustor is evaluated from pressure and velocity measurement studies.The velocity,stream function and pressure distribution inside the combustor are used to elucidate the presence of recircu lation and flow reversal from the exit section of the combustor for different Reynolds numbers.A small variation in Ums velocity was observed in axial direction while in the radial direction it was quite high.Two recirculation zones are recognized and the strength of the recirculation was seen to increase with flow Reynolds number.The turbulence intensity in the recirculation and shear layer zone was seen to be higher than the potential core.
