Abstract
•Melting heat in third grade nanomaterials flow by a stretched Riga plate is discussed.•Viscous dissipation, heat source/sink and thermal radiation are addressed in heat expression.•Physical aspects of entropy optimization are addressed.•An isothermal first order chemical reaction at catalytic surface is scrutinized.
Here we simulate entropy and melting analyses for flow of third grade nanofluid subject to a Riga plate. Fluid flow is produced by stretched surface. Melting condition is examined. Energy equation is utilized by employing the thermodynamics first law. Radiation, heat source/sink and dissipation effects are discussed. Random and thermophoresis motion effects are also accounted. Entropy analysis is developed through thermodynamics second law. Entropy generation minimization guarantees the improvement of thermal system performance. A binary chemical reaction is also deliberated. Nonlinear differential system is reduced to dimensionless system. The obtained dimensionless systems are tackled for convergent solution using optimal homotopy analysis technique. Influences of entropy analysis, velocity, concentration distribution and thermal field against physical parameters are discussed. An improvement in modified Hartman number rises the velocity. A reverse scenario is noticed for velocity and entropy rate for melting variable. Similar scenario is noted for thermal field versus random and thermophoresis motion variables. An opposite scenario is noticed for thermal field and entropy rate through radiation parameter. Decay occurs in concentration against melting variable. An increment in concentration is noted for random diffusion variable.