Articles written in Sadhana
Volume 42 Issue 2 February 2017 pp 193-211
The understanding of basic feature of energy transport from a heat source is important from the fundamental point of view as well as from various engineering and technological applications. To enrich the knowledge in this area, this paper presents energy transport phenomena from the heated bottom of an air-filled enclosure using heatfunction and heatlines. Both upward motion and downward motion of sidewalls and the alteration of cooling between sidewalls and top wall are considered, which yields four different cases. All the cases are investigated to identify the proper combination of wall motion and thermal condition for better thermal performance, considering different convection regimes. The highly nonlinear nature of flow is solved numerically using an in-house code, taking into account different speeds of wall motion and relative strength of buoyantflow and shear flow. The results reveal that the case with side cooling and downward translation of sidewalls performs maximum heat transfer compared with other cases. Higher speed of wall translation also causes higher heat transfer. Under natural convection regime, heat transfer is significantly high. Furthermore, the order of thermal mixing in a cavity is analysed and it is found that top cooling causes higher thermal mixing. To demonstrate the vortical flow structure in the cavity, streamfunction and streamlines are used. Evolutions of symmetric and asymmetric flow vortices with centre and saddle points and energy recirculation cells are found in the cavity.
Volume 45 All articles Published: 3 September 2020 Article ID 0224
The present study examines mixed convection in a ventilated cavity saturated with porous substance and heated at the right-bottom and top-left corners under the influence of uniform magnetic field applied externally. The analysis is carried out numerically using in-house CFD code. Five different heating configurationsare analyzed. The effects of pertinent parameters such as Reynolds number (Re = 1–1000), Richardson number (Ri = 0.1–100), Darcy number (Da = 10-7–10-3), Hartmann number (Ha = 1–100), angle of magnetic field (c = 0–180°) and porosity (e = 0.1–1.0), on the flow and temperature fields are examined for the search of the appropriate configuration yielding optimum heat transfer rate. Furthermore, heat transfer characterization at different heating configurations and parametric combinations is assessed
Volume 45 All articles Published: 4 September 2020 Article ID 0227
The fluid flow and convective heat transfer occurring in a lid-driven cavity which is filled with electricity conductive fluid and subjected to external magnetic field, is analyzed comprehensively. The variations in inclination angle of magnetic field and its strength are addressed during the investigation. The cavity is heatedby a linearly varying heat source applied on the left wall. Different regimes of heat transfer are considered by varying pertinent flow-parameters namely Reynolds number (Re), Richardson number (Ri) and Hartmann number (Ha). The effects of magnetic field and the wall motion are studied extensively. The study is carried out using a well-validated in-house CFD code based on finite volume method and SIMPLE algorithm. The obtained results reveal strong influence of Ri and Ha on the heat transfer characterization