Horizontal Chimney Effect

Abstract

An analysis of natural convection in horizontal slots has been carried out. It is demonstrated that a proper combination of heating and groove patterns can create a net horizontal fluid movement which we refer to as the horizontal chimney effect. Groove shapes that can be easily manufactured as well as heating patterns that can be easily created using heating wires were considered. It has been shown that both patterns must be properly tuned. The direction of the net horizontal flow can be changed by changing the relative positions of the patterns. Changes of groove geometry can change the flow rate by up to 100%. Simultaneous use of grooves and heating at both plates can nearly double the system effectiveness. The strength of the flow increases with reduction of the Prandtl number.

Use of heated corrugations for propulsion

“…More recent contributions were focused on the thermal drift created by the interaction of groove and heating patterns (Abtahi & Floryan 2017; Inasawa et al. 2021) through the pattern interaction effect (Floryan & Inasawa 2021) on pumping driven by thermal drift (Floryan, Haq & Panday 2022), on propulsion driven by nonlinear thermal streaming (Floryan, Panday & Aman 2022) and on nonlinear streaming created by distributed wall transpiration (Jiao & Floryan 2021 a , b ).…”

The reduction of pressure losses in thermally modulated vertical channels

“…It is unclear how this system response might change should the channel be orientated vertically. The limited results concerning natural convection in vertical and oblique channels suggest that a net buoyancy force can be generated even by periodic heating with zero mean and this gives rise to a propulsive force (Floryan, Haq & Panday 2022 b ; Floryan et al. 2022 c ).…”

“…It is important to emphasize that our concern is exclusively with laminar flow and the thermal modulation of turbulent flows is outside the scope of our interest. Our starting point is provided by recent study of natural convection in smooth inclined slots exposed to a patterned heating (Floryan et al 2022b) which predicts the formation of a net buoyancy force even for purely periodic heating patterns. A study of natural convection in a vertical grooved slot shows the importance of the pattern interaction effect and thermal streaming in such configurations (Floryan et al 2022c).…”