The performance of the conventional engine-cooling system has always been constrained by the passive nature of the system and the need to provide the required heat-rejection capability at high-power conditions. This leads to considerable losses in the cooling system at part-load conditions where vehicles operate most of the time. A set of design and operating features from advanced enginecoolin...

As one of the most widely used units in water cooling systems, the closed wet cooling towers (CWCTs) have two typical counter-flow constructions, in which the spray water flows from the top to the bottom, and the moist air and cooling water flow in the opposite direction vertically (parallel) or horizontally (cross), respectively. This study aims to present a simplified calculation method for c...

Air-conditioning plants With air as working fluid In open cycle have been wtdely employed and they provtde high performances In terms of compactness and low weight. In the on-aboard systems Interesting developments have been obtained as well as In the land applications same good improvements can be expected. As a matter of fact the absolute lack of pollution problems and the compactne:ss can ma...

Ejector refrigeration is a promising technology for the integration into solar driven cooling systems because of its relative simplicity and low initial cost. The major drawback of such a system is associated with its relatively low coefficient of performance (COP) under variable operating conditions. In order to overcome this problem, an advanced ejector was developed that changes its geometri...

In many industrial processes, heat exchangers play the important role of the cooling function. The effective heat transfer rate in a specific process strongly depends on the heat exchanger design. The most popular type of heat exchangers commonly used in the automotive industry, is called "radiator". In engines, radiators play the important role of the cooling process. The present study is de...

A high flux electronic chip was numerically and experimentally simulated to investigate pool boiling capabilities of enhanced metallic surface attachments built upon a 12.7 x 12.7 mm base area. It is shown how experimental nucleate boiling data for aflat chip and for chips with low-profile microstructures can be used as input boundary conditions in the numerical prediction of boiling performanc...

In this work, we discuss an extension of the set of principles that should guide the future design and development of skeletal programming systems, as defined by Cole in his ‘‘pragmatic manifesto’’ paper. The three further principles introduced are related to the ability to exploit existing sequential code as well as to the ability to target typical modern architectures, those made out of heter...

This paper presents a model-based supervisory control strategy for online control of building central cooling water systems to enhance their energy efficiency. Simplified chiller and cooling tower models are developed and used to predict the system energy performance, environment quality as well as the system response to the changes of control settings. A novel and simple optimization technique...

This study evaluates the performance of air source heat pump (ASHP) and ground source heat pump (GSHP) systems individually and as part of their associated heating and cooling distribution systems in two semi-attached houses. Over the monitoring period, the performance of both heat pumps exceeded manufacturer and EnerGuide ratings, with Coefficients of Performance (COPs) above 5 in the cooling ...

T he cooling performance of oil is critical to the functionality and durability of vehicle drive units, such as transmissions and differentials. Traditionally, automotive R&D teams evaluate cooling performance by building prototypes, installing them in a vehicle, and conducting tests in wind tunnels. The use of free-surface multiphase flow modeling with high-performance computing (HPC) has made...