Evaluation of heat transfer when variing the attack angle of a helical turbulator in a combustion gas pipe, through computational simulation

Abstract

The objective in this research have toevaluate the heat transfer of combustion gases by computer simulation by inserting a helical turbulator into a gas tube, varying its design parameters to redistribute gases and achieve an increase in gas turbulence with a certain degree of control his regime;this has been achieved by varying the angle of attack and the number of helical blades. Computerized simulation was used to predict heat transfer, the authors Zhang et al.2009, Taher et al., 2012 & Jian et al., 2015used the COMSOL MultiphysicsSoftware as a non-Isothermal Multifisic Turbulent Flow model. k-ε and the Kays-Crawford turbulent conductivity model. We evaluated the heat transfer parameters, the heat transfer coefficient that increases as the angle of attack decreases with range of [20º-80º] for the following parameters, with optimum angle of 65º, pressure drop 131 푃푎, kinetic energy of turbulence 2.11 푚2/푠2and vorticity 1.05푥104 1/푠, coefficient of heat transfer equivalent 18956 W / 푚퐾for the case under study. It was concluded that the values analyzed of heat transfer and gas flow rate have optimal parameters from which vibrations and unwanted pressure drop are reduced (Goyder, 2002), whose results indicated that the optimum angle of attack is 65º, achieving an increase inheat transfer of up to 15.1%, which produced an effect, increasing the speed by 40%.