• An adjoint-based shape optimization method minimized the drag of a surface heat exchanger for an array transfer constraint values. Optimal geometry changed from smooth to finned as load increased. The designs optimized using conjugate model were smaller than those with convection-only model. fins designed by optimizer had forward tilt reduce aft adverse-pressure gradient and consequently sepa...

an investigation has been carried out on the temperature of a biscuit on the cooling line of razavi food industries company. for thispurpose, the time variations of biscuit’s top surface temperature in traveling from oven to packing station on the conveyor packing station by conveyors has been studied. the fourier field equation for transient heat transfer is used as the basis for the determini...

In this study, by using the finite volume method, the heat transfer in a convective straight fin with temperature-dependent thermal properties and an internal heat generation under multi-boiling heat transfer modes are analyzed. In this regard, the local heat transfer coefficient is considered to vary within a power-law function of temperature. In the present study, the coexistence of all the b...

the performance of a γ-al 2 o 3 /n-decane nanofluid shell-and-tube heat exchanger in a biomass heating plant is analyzed to specify the optimum condition based on the maximum heat transfer rate and performance index for wide range of nanoparticle volume fraction (0–7%). compared with pure          n-decane, the obtained results in this research show that by using γ-al 2 o 3 /n-decane nanofluid ...

if an air flow is injected into a liquid fluid, many ambulant air bubbles are formed inside the fluid. air bubbles move inside the liquid fluid because of the buoyancy force, and the mobility of these air bubbles makes sizable commixture and turbulence inside the fluid. this mechanism was employed to enhance the heat transfer rate of a horizontal double pipe heat exchanger in this paper. howeve...

There are a number of safety and heat transfer issues in the lower plenum (LP) of a prismatic core very high temperature reactor (VHTR), such as the formation of hot spots in the lower support plate and thermal stratification of the helium gas coolant. In this paper, results of key separate-effect validation and verification (V&V) calculations, as well as the calculated flow fields and heat tra...

This paper presents an integrated flow-thermomechanical analysis of ansiothermal fatigue behavior of ceramic ball grid array (CBGA) solder joints in a 32mm C4/CBGA package under a mini power cycled load of one to three watts at a frequency of three cycles per hour. A computational fluid dynamics model was used for conjugate conduction-convection heat transfer analysis to determine the local hea...

This study considers CFD simulations with conjugate heat transfer performed in the framework of designing a complex micro-scale cooling geometry. The numerical investigation of the three-dimensional, laminar flow (Reynolds number smaller than 480) and the solid conduction is done on a reduced model of the heat sink micro-structure to enable exploring a variety of configurations at a limited com...

Helical coil heat exchangers are widely used in industrial applications ranging fromcryogenic processes, air-conditioning, and nuclear reactors to waste heat recovery due totheir compact size and high heat transfer coefficient. In this kind of heat exchangers, flowand heat transfer are complicated. This paper reports a numerical investigation of theinfluence of different parameters such as coil...