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Showing 2 results for Bluff Body
Mohammad Hossein Saberi Moghaddam, Kiumars Mazaheri, Ali Reza Alipoor,
Volume 14, Issue 13 (3-2015)
Abstract
The present numerical study investigates the effect of a bluff body on outer wall temperature of a micro scale combustor. Combustion of lean premixed hydrogen-air mixture is simulated in two dimensional domain utilizing detailed chemistry of Li et al. (13 species with 19 chemical reactions) and different mass diffusivity for each species. The effect of bluff body in combustor is studied in two viewpoints: shape of bluff body and number of bluff bodies. Two shapes of bluff body, square and triangular shapes, are considered to study the combustion efficiency and outer wall temperature. The results indicate that the shape of bluff body does not have important effect on outer wall temperature. However, triangular shape outer wall temperature is slightly more than square shape. Results also show that combustion efficiency of the square bluff body is larger than the triangular one. In second part, the effect of number of bluff bodies (i.e. one, two and four bluff bodies) on the micro scale combustor is examined on combustion characteristics. With increasing the number of bluff bodies, the outer wall temperature increases. This is due to the formation of a uniform temperature field in the micro scale combustor.
M. Tahani , M. Kazemi , Z. Babaie ,
Volume 19, Issue 9 (9-2019)
Abstract
Today, one of the useful methods of flow control, especially external aerodynamics, is plasma DBD actuators. In this study, the effect of plasma DBD actuators on cylinders in tandem arrangement is investigated. The actuators are considered on upstream cylinder. The cylinders are placed in distance (L/D) relative to each other. Investigation is done at two Reynolds number (100 and 200) with two different conditions of applying actuators. Cases with Vp-p=55kv and Vp-p=1kv are selected from references. The results of the present study are validated against the previous available experimental and numerical data and close agreement is found. Finite volume method is applied to solve equation of motion. Plasma actuators caused downstream cylinder experience upper values of drag coefficient and Nusselt number in all cases of study. Also, the growth of drag coefficient and Nusselt number are decreased by rising the Reynolds number, so that increasing the Nusselt number is 2% more at cases with Re=100 compared to cases with Re=200.
