In this paper, we present experimental investigation of convective heat transfer characteristic in the inner tube fluid of miniature concentric double tube Hair-pin heat exchanger with constant heat flux. This work is carried out for distilled water and a mixture of distilled water and ethylene glycol (10%, 20% and 25% by volume) as heat transfer cold fluid flowing in inner tube to carry away h...

Shrinking the engine has been a great interest for many years. Providing more amount of heat transfer may supply possibilities for size reduction in engine parts specifically the engine water jacket that is of concentration for the present study. Boiling phenomenon, by providing more amounts of heat transfer in comparison with single-phase, provides conditions for size reduction. In this paper ...

Experimental investigation of heat transfer during pool boiling of two nanofluids, i.e., water-Al2O3 and water-Cu has been carried out. Nanoparticles were tested at the concentration of 0.01%, 0.1%, and 1% by weight. The horizontal smooth copper and stainless steel tubes having 10 mm OD and 0.6 mm wall thickness formed test heater. The experiments have been performed to establish the influence ...

Nucleate pool boiling heat transfer coefficient have been experimentally measured on a horizontal rod heater for various liquid binary mixtures. Measurements are based on more than three hundred data points on a wide range of concentrations and heat fluxes. In this investigation, it has been confirmed that the heat transfer coefficient in boiling solutions are regularly less than those in p...

It is shown that there exists an optimal spacing of thermo-sensors in the determination of the experimental heat transfer coefficient of a fluid flowing over a plate. The problem is considered as an inverse heat transfer problem with long thin fin model. The heat transfer coefficient of the fluid is estimated from simulated steady-state temperature measurements along the plate. It is shown theo...

Accurate and optimum usage of energy sources is gaining importance all over the world due to the increase of energy need and limited energy sources. Optimum usage of energy sources is not only necessity for energy conversion systems, but also design and production of energy conversion devices. Therefore optimization of condensers is very important for HVAC systems which require as possible as m...

Abstract. This paper presents results of an experimental study on heat exchanger consisting of finned tube.The presented method for determining the local heat transfer coefficient on external tube surfaces is characterized by very high accuracy and can be applied to determine the spatial heat transfer distribution on objects with a complex shape. As a results of experimental and numerical inves...

The present paper is an experimental investigation of roughness effects on nucleate pool boiling of refrigerant R113 on horizontal circular copper surfaces. The copper samples were treated by different sand paper grit sizes to achieve different surface roughness. The average surface roughness of the four samples was 0.901, 0.735, 0.65, and 0.09, respectively. The experiments were performed in t...

Natural convection heat transfer was investigated experimentally in a concentric-cylinders annulus. To enhance the rate of heat transfer, pin fins were installed on the surface of the inner cylinder. Two fin arrangements were employed, namely, staggered and in-line arrangements. The length of the fins varied from 2 to 8 cm and the Rayleigh number Ra changed in the range from 5 x 105  to 5 x 106...

The condensation heat transfer coefficient of R134a was experimentally studied inside two smooth and four micro-fin tubes. The working conditions and structural parameters of the test tubes were selected as the influencing factors, and the experiment was conducted under mass velocities of 400–1100 kg·m−2·s−1, condensation temperatures of 35–45 ◦C and water-testing Reynolds numbers of 8000–22,00...