This paper reports an experimental study on nanofluid convective boiling heat transfer in parallel rectangular minichannels of 800 μm hydraulic diameter. Experiments are conducted with pure water and silver nanoparticles suspended in water base fluid. Two small volume fractions of silver nanoparticles suspended in water are tested: 0.000237% and 0.000475%. The experimental results show that the...

We describe a theoretical model of the fluid flow, heat transfer and phase change which occurs when liquid is injected into a fracture bounded by a hot, impermeable rock. We first consider the case of a warm host rock, in which there is no boiling of the water. We then develop the model to describe the case in which the host rock temperature is in excess of the boiling temperature and the water...

One of the most practical means of measuring this important variable is by the temperature of the boiling syrup at a known absolute pressure or by reference to the temperature of water boiling at the same pressure. The so-called “Boiling Point Elevation” or “BPE” has long been used for this purpose. A considerable amount of care must be exercised in making the temperature measurements if they a...

This paper presents a new numerical model, called the CAS model, for boiling heat transfer. The CAS model is based on the cellular automata (CA) technique that is integrated into the popular SIMPLER algorithm for CFD problems. In the model, the CA technique deals with the microscopic nonlinear dynamic interactions of bubbles while the traditional CFD algorithm is used to determine macroscopic s...

Cetane numbers (C#) for the homologous series of straight-chain, saturated n-alcohols, CS-C12 and C14, were determined according to ASTM D 613. Measured C# ranged from 18.2-80.8 and increased linearly with carbon number (CN). Regression analyses developed equations that related various physical properties or molecular characteristics of these alcohols to calculated CU. The degree of relationshi...

This work describes an improved design for a nuclear fuel rod, which was developed using an experimental circuit that simulates the nuclear rod environment in a pressurized water reactor (PWR). The heat exchanger circuit runs atmospheric to high-pressure boiling water through an annular finned tube (153 fins), which is used to enhance confined heat transfer rates and guide the nucleate boiling ...

Nucleate pool boiling heat transfer coefficients of Al2O3-water and TiO2-water nanofluids have been experimentally measured on three horizontal tubes with different materials and similar roughness under atmospheric pressure. Results revealed that the presence of nanoparticles in the base fluid leads to an increase in pool boiling heat transfer coefficients on stainless steel and brass tubes in ...

A high power electronic chip was simulated experimentally to investigate upper cooling capabilities using a variety of pool boiling enhancement techniques. Parametric effects of system pressure, subcooling, surface augmentation, and choice of coolant on boiling heat transfer from a vertical 12.7'x 12.7 mm flat surface were examined. The two fluorocarbon coolants tested, FC-72 and FC-87, resulte...

There are numerous technical applications where hot components, with uneven temperature distribution, require cooling. In such applications, it is desired to provide efficient local cooling of the spots, while avoiding unnecessary over-cooling other regions. Such an approach, known as precision cooling, has several advantages. addition fact that reduces effort for limits unintended heat lost me...