Heat exchangers play significant role in refrigeration and air conditioning systems. Ongoing research aims to improve, or at least maintain, the system performance while reducing the size, weight and cost of the heat exchangers. This in turn leads to lower system refrigerant charge and reduced environmental impact. Using heat exchangers with small tube diameters (less than 5 mm) instead of larg...

Due to their large surface-area-to-volume ratio and tortuous structure, metal foams hold promise for heat transfer applications. Both of these factors increase the heat transfer by enhancing the mixing and surface area. The main disadvantage associated with their thermal-hydraulic performance is relatively higher pressure drop, resulting in larger pumping power requirements if they are used in ...

Title of Dissertation: CHARACTERIZATION, MODELING, AND OPTIMIZATION OF POLYMER COMPOSITE PIN FINS Raj Bahadur, Doctor of Philosophy, 2005 Directed By: Professor, Avram Bar-Cohen, Mechanical Engineering Increasing electronic product manufacturing volumes and cooling requirements necessitate the use of new materials and innovative techniques to meet the thermal management challenges and to contri...

Triclosan (TCS) and triclocarban (TCC) are widely used broad spectrum bactericides that are common pollutants of waterways and soils. Methyl triclosan (mTCS) is the predominant bacterial TCS metabolite. Previous studies have shown that TCS disrupts thyroid hormone (TH) action; however, the effects of mTCS or TCC are not known. The present study uses the cultured frog tadpole tail fin biopsy (C-...

A numerical optimization tool is used to optimize forced convection micro-channel heat sinks for minimum pump power at high heat fluxes. Results gained with the optimization tool are generalized and optimum configurations are illustrated on design charts. Physical trends are illustrated analytically using the underlying relations. Investigations are done for air and water in single-phase flow w...

The steady heat transfer through a rectangular longitudinal fin is studied.The thermal conductivity and heat transfer coefficient are assumed to be temperature dependent making the resulting ordinary differential equation (ODE) highly nonlinear. An asymptotic solution is used as a means of understanding the relationship between key parameters. A dynamical analysis is also employed for the same ...

Liquid behaviors, including droplet condensation and frost melt water retention, of fins during frosting and defrosting processes on three aluminum fins with different surface characteristics under winter operating conditions of an air source heat pump were investigated. The effects of the surface characteristics, including the contact angle and the contact angle hysteresis, were analyzed. Drop...

Based on the model of battery temperature rising established, several kinds of temperature rising processes are analyzed by means of numerical simulation including heat dissipation by natural convection without fin or with fin and forced convection with fin. The comparison and analysis are made for temperature rising process about their temperatures of center and across section plane. It shows ...

Latent thermal energy storage (LTS) systems are versatile due to their high-energy storage density within a small temperature range. In shell-and-tube type storage systems fins can be used in order to achieve enhanced charging and discharging power. Typically, circular fins are evenly distributed over the length of the heat exchanger pipe. However, it is yet to be proven that this allocation is...