Assessment of fluid behavior containing nanoparticles exhibit exciting dimensions in fluiddynamics and offer huge potential for various sectors such as energy, aerodynamics andbiomedical and engineering industries.Nanofluid suspensions contains nanomaterial (1-100nm), were studied under different scenarios that can be exclusively categorized in threesections.The first study was focused on biconvective flow of Powell-Eyring nanofluidpassing over stretched surface.Aim of this study was to investigate the role of gyrotacticmicroorganisms in heat and mass transfer in the presence of magnetohydrodynamic (MHD)forces.A novel approach based on homotopy analysis method (HAM) was employed topresent series solution for Newtonian heating effects in the presence of thermophoretic mechanism and Brownian motion.Mathematical model presented the boundary layer regime thatinvolved contemporary non linear partial differential equations converted into the ordinarydifferential equations.Nanofluid flow characteristics investigated in this study comprised ofvarious parameters that include bioconvection Lewis number Lb, traditional Lewis numberLe, bioconvection Péclet number Pe, buoyancy ratio parameter Nr, bioconvection Rayleighnumber Rb, thermophoresis parameter Nt, Hartmann number M, Grashof number Gr, andEckert number Ec.Findings showed significant effect of Newtonian heating over a stretchingplate for skin friction, local Nusselt number and the local density number of microorganism.Results indicated that microorganisms stabilized the nanoparticle suspension in response tobioconvection generated by combined effects of buoyancy forces and magnetic field.Secondpart of research work was devoted to analyze mixed convection flow in the presence ofchemical reaction and heat absorption/generation.This study also kept gyrotactic microorganisms and nanoparticles whereas flow was carried out using Powell-Eyring nanofluids.The objective was to present series solutions for key partial differential equations to betransformed in to an appropriate set of ordinary differential equation.For this purpose, HAMwas applied to compute pertinent nanofluid characteristics.The final model presented showedsignificant effects of Brownian motion and thermophoresis on flow regime for bioconvectivepatterns for microorganism.It was concluded that velocity profile decreases by increasingfluid paramter δ as well as by increasing Rb and Nr.Additionally, it was also revealed thatboth the temperature and concentration of nanoparticle increase with the corresponding risein Nt values.　　The last part of this research work was distinctly emphasized on squeezing flow of carbonnanotubes (CNTs) between two parallel Riga plates.Kerosene oil was used as based fluidwhereas for maintaining the presence of nanoparticles, carbon nanotubes were used.Boththe single-wall and multi-wall carbon nanotubes were used for comparison of kerosene oilbased squeezing flow.The model investigated here assumed that CNTs were homogeneously　　distributed in the kerosene oil and nanofluid squeezing flow is taking place in an unsteadyform passing through two parallel Riga plates.The analytical approach employed in thispart of study was also based on homotopy analysis method with an aim to explore heattransfer characteristics with viscous dissipation and convective boundary conditions.A setof non-linear differential equations for the governing flow is attained by employing suitabletransformations through the conservative laws.Finding of this study successfully highlightedthe behavior of different emerging parameters on the velocity and temperature distributions.Furthermore, it was revealed that velocity is smaller for squeezing parameter in the caseof multi-wall CNTs when compared with single-wall CNTs.Finally it was concluded that　　temperature profile decreased for single-wall CNTs than the mulit-wall when volume fractionof nanoparticles increase.