There is a need for a hand-heating system that will keep the hands warm during cold exposure without hampering finger dexterity. The purpose of this study was to examine the effects of torso heating on the vasodilative responses and comfort levels of cooled extremities during a 3-h exposure to -15 degreesC air. Subjects were insulated, but their upper extremities were left exposed to the cold a...

research in convective heat transfer using suspensions of nanometer-sized solid particles in base liquids started only over the past decade. recent investigations on nanofluid, as such suspensions are often called, indicate that the suspended nanoparticles remarkably change the transport properties and heat transfer characteristics of the suspension. bending walls can also improve heat transfer...

As the scale of devices becomes small, thermal control and heat dissipation from these devices can be effectively accomplished through the implementation of microchannel passages. The small passages provide a high surface area to volume ratio that enables higher heat transfer rates. High performance microchannel heat exchangers are also attractive in applications where space and/or weight const...

Cross flow water tube heat exchanger can be designed and made operational using methods of model building and simulation of the system. This paper projects the design and development of a model of cross flow water tube heat-exchanger system, simulation and validation of control analysis of different tuning methods. Feedback and override control system is developed using inputs acquired with the...

An analytical investigation is conducted to study the unsteady free convection heat and mass transfer flow through a non-homogeneous porous medium with variable permeability bounded by an infinite porous vertical plate in slip flow regime while taking into account the thermal radiation, chemical reaction, the Soret number, and temperature gradient dependent heat source. The flow is considered u...

Active heat flow control is essential for broad applications of heating, cooling, and energy conversion. Like electronic devices developed for the control of electric power, it is very desirable to develop advanced all-thermal solid-state devices that actively control heat flow without consuming other forms of energy. Here we demonstrate temperature-gated thermal rectification using vanadium di...

Precise design and operational control of the polymerase chain reaction process is key to the performance of on-chip DNA analysis. This research is dedicated to understanding the fluid flow and heat transfer mechanisms occurring in continuous flow PCR chips from the engineering point of view. In this work, a 3-dimensional model was developed to simulate the electrical potential field, the flow ...

An analytical model for a condenser with a wetted surface is developed by applying the governing conservations and rate equations and invoking the heat and mass transfer analogy. The heat exchanger is discretized in both the airflow and refrigerant-flow directions for a cross-flow configuration. Axial conduction along the tube walls is neglected and uniform distribution of water is assumed at t...

– The idea that one can build a solid-state device that lets heat flow more easily in one way than in the other, forming a heat valve, is counter-intuitive. However the design of a thermal rectifier can be easily understood from the basic laws of heat conduction. Here we show how it can be done. This analysis exhibits several ideas that could in principle be implemented to design a thermal rect...

During exercise, circulatory reflexes ensure that the cardiac output is sufficiently elevated to meet the oxygen delivery requirements of the contracting skeletal muscles and the heat delivery requirements of the body to the skin. The latter requirements are met by increasing skin blood flow. These increases are largely driven by elevations in the body temperatures, although non-thermal effects...