Abstract: Confronted with noise disturbance during transmission of vehicle exhaust air, several mufflers have been designed to control the noise and improve the transmission characteristics. In order to optimize the noise control and attenuation quality, the internal geometry, inlet and outlet pipe diameters of a designed muffler were varied and the performance evaluated using finite element method (FEM). Furthermore, 2mm diameter equal circular perforations were introduced in the resonator chamber to verify the effect on the transmission loss characteristics. The results show that the performance of the muffler with inlet pipe diameter variation is significantly better (68dB) than the standard muffler (55dB) in controlling and reducing acoustic wave propagation within the same frequency range of (200~580Hz). The performance improved further to 70 dB by the introduction of circular perforations in resonator chamber. However, with the variation in the outlet diameter increase the performance of the muffler was 55dB but within a higher frequency range of 220~680Hz which is not reliable for acoustic wave propagation control. The average transmission loss performance of the designed mufflers were 48.62, 47.77, 39.01 and 37.77dB for the resonator chamber perforation, inlet pipe diameter increase, outlet pipe diameter increase and standard muffler respectively. Therefore, the designed muffler with resonator chamber perforations is the best for optimal acoustic wave control.Abstract: Confronted with noise disturbance during transmission of vehicle exhaust air, several mufflers have been designed to control the noise and improve the transmission characteristics. In order to optimize the noise control and attenuation quality, the internal geometry, inlet and outlet pipe diameters of a designed muffler were varied and the performa...Show More
Abstract: Solar collectors have always been radical tools in the theoretical field of mechanical engineering as well as for any relevant establishment. Owing to uplifting demand for renewable energy sources, the investment for solar collector use is augmenting. Apart from flat plate or regular types, hybrid heat pipe solar collector could be taken for a neoteric type of solar collector. This research work aimed at designing and setting up a hybrid heat pipe solar collector and to evaluate the efficiency. A hollow copper pipe was used as heat pipe whose bottom end was closed by brazing a tiny solid copper block. Later the copper pipe was filled with acetone as the working fluid of heat pipe and by a burner, the bottom end of the pipe was heating until the pipe was filled with the vapor of acetone and then top of the pipe was closed by soldering. All other heat pipes, made of the same approach, were assembled then to an absorber plate touching the heat pipes forming the entire layout of heat pipe solar collector. The structure was then examined in the month of November and December and provided peak efficiency of about 27.44%. The efficiency could be properly enhanced by further research and examination of the methodology of fabricating the heat pipes.Abstract: Solar collectors have always been radical tools in the theoretical field of mechanical engineering as well as for any relevant establishment. Owing to uplifting demand for renewable energy sources, the investment for solar collector use is augmenting. Apart from flat plate or regular types, hybrid heat pipe solar collector could be taken for a neot...Show More