Forced convection in a channel with transverse fins

Abstract

PurposeTo make the finned exchanger light and compact, the design of optimized fins has become increasingly important nowadays. The purpose of this paper is to present a numerical investigation on forced convection in a horizontal parallel plate channel with inline transverse fins on channel walls.Design/methodology/approachThrough the use of a stream function vorticity transformation, solution of the transformed governing equations for the system is obtained using the control‐volume method with non‐uniform grid. The extrapolated‐Jacobi scheme was used to solve the finite‐difference equations.FindingsFor fins with fixed fin volumes, the array fins of optimum aspect ratios which dissipate maximum heat transfer in a parallel‐plate channel are obtained. For these optimum fins, it shows that the first fin is the shortest and the height of the rest of fins increases along the downstream direction of the channel. In addition, the optimum aspect ratio of a fin increases with Reynolds number and fin spacing but decreases with thermal conductivity ratio and entrance length with other parameters fixed.Originality/valueThis is the first paper devoted to the exploration of the optimized fin array in a forced convective channel, considering heat conduction in the fins and heat convection in the fluid simultaneously.

Baffle orientation and geometry effects on turbulent heat transfer of a constant property incompressible fluid flow inside a rectangular channel

“…"transverse or longitudinal" (Ben Slama, 2007;Pirouz et al, 2011), "parallel, orthogonal or inclined" (Demartini et al, 2004;Won et al, 2004;Nasiruddin and Siddiqui, 2007), "solid, perforated or porous" (Ko and Anand, 2003;Sahel et al, 2016) and "simple, corrugated or shaped" (Taslim and Li, 1996;Lei et al, 2008;Zhou and Ye, 2012;Jedsadaratanachai and Boonloi, 2014;Ünalan et al, 2007) type obstacles, known as "vortex generators" (Fiebig et al, 1991) "elements" (Habib et al, 1988), "turbulators" (Han and Park, 1988), "deflectors" (Demartini et al, 2004), or "disturbance promoters" (Han et al, 1985), such as "ribs" (Karwa, 2003;Nguyen et al, 2017), "fins" (Kelkar and Patankar, 1987;Sheremet and Chinnasamy, 2018;Yang et al, 2012;Kahalerras and Targui, 2008) or "baffles" (Berner et al, 1984;Ho and Ramaswamy, 1995;Armaghani et al, 2018), placed on or near the insulated and/or heated channel walls (Dutta and Hossain, 2005;Tanda, 2011) with in-line or staggered manners (Tamna et al, 2014). This is because the obstacle helps to interrupt the hydrodynamic and thermal boundary layers and to induce a vortex downstream (Sripattanapipat and Promvonge, 2009).…”

“…One of the most effective passive techniques for improving the convective heat transfer rate in smooth air channels, such as “heating, cooling or solar” ducts (Verma and Prasad, 2000; Aharwal et al , 2008; Mehryan et al , 2018; Tahmasebi et al , 2018; Ghalambaz et al , 2014a, 2014b; Ghalambaz and Noghrehabadi, 2014; Behseresht et al , 2014; Noghrehabadi et al , 2013) at “low, moderate or high” Reynolds numbers (Hwang and Lin, 1999; Endres and Möller, 2001; Maurer et al , 2007; Mansour et al , 2016; Ahmed et al , 2013; EL-Kabeir et al , 2007; Rashad, 2008; Rashad et al , 2011; Shuja et al , 2010), is the use of “attached, semiattached or detached” (Liou and Wang, 1995; Liu and Wang, 2011; Yongsiri et al , 2014), “transverse or longitudinal” (Ben Slama, 2007; Pirouz et al , 2011), “parallel, orthogonal or inclined” (Demartini et al , 2004; Won et al , 2004; Nasiruddin and Siddiqui, 2007), “solid, perforated or porous” (Ko and Anand, 2003; Sahel et al , 2016) and “simple, corrugated or shaped” (Taslim and Li, 1996; Lei et al , 2008; Zhou and Ye, 2012; Jedsadaratanachai and Boonloi, 2014; Ünalan et al , 2007) type obstacles, known as “vortex generators” (Fiebig et al , 1991) “elements” (Habib et al , 1988), “turbulators” (Han and Park, 1988), “deflectors” (Demartini et al , 2004), or “disturbance promoters” (Han et al , 1985), such as “ribs” (Karwa, 2003; Nguyen et al , 2017), “fins” (Kelkar and Patankar, 1987; Sheremet and Chinnasamy, 2018; Yang et al , 2012; Kahalerras and Targui, 2008) or “baffles” (Berner et al , 1984; Ho and Ramaswamy, 1995; Armaghani et al , 2018), placed on or near the insulated and/or heated channel walls (Dutta and Hossain, 2005; Tanda, 2011) with in-line or staggered manners (Tamna et al , 2014). This is because the obstacle helps to interrupt the hydrodynamic and thermal boundary layers and to induce a vortex downstream (Sripattanapipat and Promvonge, 2009).…”

Design of Infrared Radiation for Best Heat Source Performance In Paint Cure Oven

“…The Little thermal inertia of the radiation by infrared removes the necessity of long preheats cycles [14]. Infrared heating is less than one-third of that of that of convectional ovens [10]. Since there is no medium required for transferring heat, infrared heating is much faster than others [6].…”

Mixed Convection and Entropy Generation of an Ag-Water Nanofluid in an Inclined L-Shaped Channel

“…Separation and reattachment of the flow in backward-and forward-facing steps were proven to give an improvement to efficient heat transfer [3]. Finned or ribbed wall surfaces are also implemented as a passive strategy to improve the mixing of flow and increase the area of heat transfer [4][5][6].…”