In general, nanofluid is suspension of nanometer-sized particle in base fluids such as water, oil, ethylene glycol mixture etc. Nanofluid has more thermal conductivity compared to the base fluids. As such, the nanofluid has more heat transfer capacity than the base fluids. In order to study nanofluid flow problems, we need to solve related nonlinear differential equations analytically or numerically. But in most cases, we may not get an analytical solution. Accordingly, the related nonlinear differential equations need to be solved by efficient numerical methods. Accordingly, this book addresses various challenging problems related to nanofluid flow. In this regard, different efficient numerical methods such as homotopy perturbation method, Galerkin's method, and least square method are included. Further, the above practical problems are validated in special cases. We believe that this book will be very beneficial for readers who want firsthand knowledge on how to solve nanofluid flow problems.