Entropy Analysis of a Convective Film Flow of a Power-Law Fluid with Nanoparticles Along an Inclined Plate
B. Vasu1, R. S. R. Gorla2, P. V. S. N. Murthy3, Beg O. Anwar4
1Motilal Nehru National Institute of Technology Allahabad, Prayagraj, 211004 India
2Cleveland State University, Ohio, 44115, USA
3Indian Institute of Technology Kharagpur, Kharagpur, India
4Salford University, Salford, M54WT, UK
Keywords: анализ энтропии, течение пленки, наножидкость, свободная конвекция, степенной реологический закон, термофорез, entropy analysis, film flow, nanofluid, free convection, power-law model, thermophoresis
Abstract
Entropy generation in a two-dimensional steady laminar thin film convection flow of a non-Newtonian nanofluid (Ostwald-de-Waele-type power-law fluid with embedded nanoparticles) along an inclined plate is examined theoretically. A revised Buongiorno model is adopted for nanoscale effects, which includes the effects of the Brownian motion and thermophoresis. The nanofluid particle fraction on the boundary is passively rather than actively controlled. A convective boundary condition is employed. The local nonsimilarity method is used to solve the dimensionless nonlinear system of governing equations. Validation with earlier published results is included. A decrease in entropy generation is induced due to fluid friction associated with an increasing value of the rheological power-law index. The Brownian motion of nanoparticles enhances thermal convection via the enhanced transport of heat in microconvection surrounding individual nanoparticles. A higher convective parameter implies more intense convective heating of the plate, which increases the temperature gradient. An increase in the thermophoresis parameter decreases the nanoparticle volume fraction near the wall and increases it further from the wall. Entropy generation is also reduced with enhancement of the thermophoresis effect throughout the boundary layer.
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