Double-diffusive convection: Flow of nanofluid of variable heat capacity inside rectangular and inclined walls

Abstract

Double-diffusive convection has been investigated in the flow of nanofluid of variable heat capacity, whereas the flow is maintained inside rectangular and inclined walls. The effective transport of heat in many engineering systems is ensured by considering the appropriate and suitable geometrical structure of such systems and the types of coolant used for those purposes. Therefore, these two key features have been the focus of this investigation. The well-known Buongiorno model is taken for the flow of nanofluid of variable heat capacity, whereas the fluid flow model is simulated for the upper half channel only. The governing partial differential equations are simplified and converted into a system of ordinary differential equations. The nature and behaviour of velocity, temperature and concentration (nanoparticles) profiles have been studied and analysed inside a converging–diverging channel in the presence of assisting and opposing flow cases with variation of heat capacity and thermal conductivity of nanomaterial in the base (host) fluid. Moreover, linear, nonlinear, uniform, increasing, decreasing and asymptotic nature of the field variables (velocity, temperature and concentration functions) has been found in the presence of existing parameters, whereas, the three quantities of physical interest i.e. pressure, skin friction and rates of heat and mass transfer have been determined at the upper wall of the channel against the different parameters, involved in the problem.