Unsteady Slip Flow past an Infinite Vertical Plate with Ramped Plate Temperature and Concentration in the Presence of Thermal Radiation and Buoyancy

Unsteady laminar slip flow along an infinite vertical plate with ramped plate temperature and concentration in the presence of thermal radiation and buoyancy is investigated. Approximated Navier–Stokes equation along with the energy and species equations are solved analytically by adopting the Laplace transform technique. The dependencies of the flow, heat and mass transfer characteristics on time (t), space (y) and nondimensional governing parameters, namely, slip (λ), radiation (R), buoyancy forces ratio (N), Prandtl number (Pr) and Schmidt number (Sc), are explored for both ramped and constant plate temperature and concentration conditions. The results show that radiation effect is appreciable at a lower range of R and found to be greater for the constant than that for the ramped condition. A strong flow near to the plate is generated by radiation and buoyancy effects, and accelerated by slip effect. Finally it is also shown logically and mathematically that in the absence of radiation and presence/absence of slip the flow should be brought to stationary flow when two buoyancies are opposite and equal in magnitude with equal solutal and thermal diffusions.