Nanoliquids strengthen low thermal conductivity of materials. Nanoliquid consists of nano-material (1 − 100 nm) and base-liquid. Nanoliquids are regarded functional in engineering, electronic process and many other fields. Nanoparticles include CNTs (MWCNT, SWCNT), oxides and carbides ceramics and semiconductors. These nanoparticles are submerged in an ordinary fluid to make them nanofluids. Non-Newtonian fluids like Oldroyd-B, Powell Eyring, Williamson are regarded helpful in physiological phenomena, pharmaceutical process, paper production and metallurgy. That is why Oldroyd-B, Powell Eyring and Williamson fluids are adopted in this thesis for modeling and analysis of flows in boundary layer region. The boundary-layer flows due to stretching surface have wide range of applications in industries and engineering. Further it is also taken into account that heterogeneous-homogeneous reactions in liquid flow have vital role following combustion, biochemical processes, catalysis and in many other fields. Keeping all these aspects in mind the prime objective of this thesis is to study nonlinear mathematical models subject to homogeneous-heterogeneous reactions. The structure of this thesis is as follows. Chapter 1 contains literature survey and some basic conservation laws. Mathematical model and boundary-layer expressions for Oldroyd-B, second grade, Powell Eyring and Williamson fluids are incorporated. Five different techniques are used to deal with the flow problems. Thus basic concepts homotopy analysis method (HAM), Bvp4c matlab solver, Optimal homotopy analysis method (OHAM), shooting technique and Keller box method are provided. Chapter 2 addresses the impact of diffusion species in flow of CNTs nanofluid saturating porous medium. Melting heat transfer is present. Auto catalyst and reactant have same diffusion coefficients. Flow induced by stretched cylinder. Homotopy analysis method (HAM) is adopted for solutions procedure. The outcomes for CNTs flow are disclosed. This chapter contents is reported in Journal of Molecular Liquids 221 (2016) 1121 − 1127. Chapter 3 deals diffusion species via CNTs with convective conditions. Flow generated is because of stretching cylinder. OHAM is adopted for outcomes. Graphical outcomes are discussed via variables for flow. The outcomes are reported in Journal of the Taiwan Institute of Chemical Engineers 70 (2017) 119 − 126. Chapter 4 reports computational aspects for Forhheimer flow of CNTs nanofluids with diffusion species. In this chapter thermal conductivity of CNTs nanofluid is compared via renovated Hamilton-Crosser (H-C) and Xue models for flows by stretching cylinder and flat sheet. The results are obtained via Keller box method. The findings of this chapter are submitted in Physica E for possible publication. Chapter 5 examines stagnation flow of carbon water and carbon kerosene oil nanofluids via nonlinear stretched surface. CNTs nanofluids fill the porous medium. Homogeneousheterogeneous reactions and melting effects are considered. Outcomes are obtained via (OHAM). Heat transferred is addressed via different variables involved in solutions expressions. The contents of this chapter are published in Advanced Powder Technology 27 (2017) 1677 − 1688. Chapter 6 presents 3D nanoliquid flow by stretched (nonlinear) sheet with diffusion species. Nanoliquid is saturated via porous space. Convective condition and heat source/sink are used for heat mechanism. The numerical outcomes are analyzed via shooting approach. Graphical illustrations and tabulated values are disclosed. The main findings of this chapter can be seen through Computer Methods in Applied Mechanics and Engineering 329 (2018) 40 – 54. Chapter 7 describes three-dimensional (3D) nanoliquid flow via slendering stretching (nonlinear) sheet with slip effects. bvp4c technique is used for numerical outcomes. Tabulated and graphical findings are explored via sundry variables. These contents are published in Computer Methods in Applied Mechanics and Engineering 319 (2017) 366 − 378. Chapter 8 discloses flow of MHD non-Newtonian liquid via Newtonian heating and diffusion species. Results are developed via HAM. Numerical results of skin friction and Nusselt number are disclosed. The findings of current chapter are published in PloS one 11 (6) e0156955 (2016). Chapter 9 describes flow of MHD viscoelastic fluid with species. Flow is due to stretched cylinder. Viscous dissipation, Newtonian heating and Joule heating are also accounted. The results are constructed via HAM. Characteristics of different variables are elaborated graphically. The outcomes of this chapter are published in Journal of Mechanics 33 (2017) 77 − 86. Chapter 10 includes species influence in flow of second grade material. Melting heat contribution is inspected. Inclined magnetic line is used to electrified the liquid. Numerical results are addressed via heat transfer and skin friction. The contents are addressed in Journal of Molecular Liquids 215 (2016) 749 − 755. Chapter 11 investigates homogeneous-heterogeneous reactions in thermally stratified stagnation flow of viscoelastic liquid with mixed convection. Flow is by a stretched sheet. Influences of various variables on quantities of interest are discussed. The findings of this chapter are published in Results in Physics 6 (2017) 1161 − 1167. Chapter 12 addresses convective flow of Williamson fluid by cylinder and flat sheet. Convective condition is used for heat transfer mechanism. The species of auto-catalyst and reactant are used to regulate the concentration. Convection or evaporation for temperature phase change is analyzed through homogeneous-heterogeneous reactions. The transformed ordinary differential equations are dealt numerically via Keller box method.Impacts of pertinent parameters of interest are graphically discussed. Comparison of results for cylinder and flat sheet is arranged. The contents of this chapter are submitted for possible publication in International Journal of Mechanical Sciences.