nanofluid is a new class of heat transfer fluids engineered by dispersing metallic or non-metallic nanoparticles with a typical size of less than 100 nm in the conventional heat transfer fluids.this article aims to investigate the overall and convection heat transfer coefficient and nusselt number of al2o3-water nanofluid flowing in a horizontal double pipe heat exchanger under turbulent flow (...

An experimental investigation was carried out to study mixed convection heat transfer from Al2O3-water nanofluid inside a vertical, W-shaped, copper-tube with uniform wall temperature. The tests covered different ranges of some involved parameters including Reynolds number, temperature and particles volume fraction. The results showed that the rate of heat transfer coefficient improved with Rey...

Natural convection heat transfer from a tube bundle in the indirect water bath heaters is investigated. A computer-code is used for the solution of the governing equations of mass, momentum and energy transfer based on the SIMPLE-C algorithm. Simulations are carried out for the gas pressure station heater of Kermanshah city with various tube bundle arrangements. In order to validate the numeric...

if an air flow is injected into a liquid fluid, many ambulant air bubbles are formed inside the fluid. air bubbles move inside the liquid fluid because of the buoyancy force, and the mobility of these air bubbles makes sizable commixture and turbulence inside the fluid. this mechanism was employed to enhance the heat transfer rate of a horizontal double pipe heat exchanger in this paper. howeve...

this article investigates the nonlinear, steady boundary layer flow and heat transfer of an incompressible eyring-powell non-newtonian fluid from an isothermal sphere with biot number effects. the transformed conservation equations are solved numerically subject to physically appropriate boundary conditions using a second-order accurate implicit finite-difference keller box technique. the influ...

In the design of heat exchangers, it is necessary to determine the heat transfer rate between hot and cold fluids in order to calculate the overall heat transfer coefficient and the heat exchanger efficiency. Heat transfer rate can be determined by inverse methods. In this study, the unknown space-time dependent heat flux imposed on the wall of a heat exchanger internal tube is estimated by app...

An experimental and numerical study of free convection heat transfer from a channel consisting of a vertical sinusoidal wavy surface and a vertical flat plate has been carried out. The vertical wavy surface was maintained at a constant temperature, while the flat plate is adiabatic. A Mach-Zehnder Interferometer was used to determine the local heat transfer coefficients of sinusoidal wavy surfa...

the subjects of heat transfer and cooling system are very important topics in the internal combustion engines (ice). in modern cooling systems, low weight, small size and high compactness are the critical designing criteria that requires heat transfer enhancement. boiling phenomenon which is occurred in the water jacket of the ice is one of the methods to increase heat transfer in the coolant s...