Heat Transfer Simulations

The simulations of fluid flow and heat transfer in such microstructured geometries were carried out with an FVM solver. Air with an inlet temperature of 100 °C was considered as a fluid, and the channel walls were modeled as isothermal with a temperature of 0 °C. The streamline pattern is characterized by recirculation zones which develop behind the fins at comparatively high Reynolds numbers. The results of the heat transfer simulations are summarized in Figure 2.34, which shows the Nusselt number as a fimction of Reynolds number. For... 

The validation of CFD codes by comparison to reliable experiments is of the highest importance. Especially promising is the use of MRI methods to non-invasively provide flow fields and dispersion data. Major challenges will be to extend MRI and similar methods such as LDV and particle tracking to a wider range of conditions, and to develop noninvasive measurements of temperature to improve verification of heat transfer simulations. 

First, second and 5th order polynomial interpolation for the specific heat capacity of a semi-crystalline thermoplastic (PA6). When performing a heat transfer simulation (heating or cooling) for a thermoplastic, the complete course of the specific heat capacity as a function of temperature is needed. A common way to do this... 

For CFD analysis of CVD systems, it is important to define correct boundary conditions for conservation equations. Typical example attributes of boundary conditions used in flow and heat transfer simulations are velocity, gas concentration, and temperature of the boundary areas. If an inlet boundary is selected such that it contains too many unknown initial values for the problem, one should extend the boundary area to as far as a bound where all initial variable values are known. In assigning the initial values of the boundary areas, it is a common practice to make the following assumptions [58, 59],... 

HEXTRAN heat transfer simulation and pinch analysis... 

The standard k-e model focuses on mechanisms that affect the turbulent kinetic energy. Robusmess, economy, and reasonable accuracy over a wide range of turbulent flows explain its popularity in industrial flow and heat transfer simulations. The RNG k-e model was derived using a rigorous statistical technique (called Re-Normalization Group theory). It is similar in form to the standard k-e model, but the effect of swirl on turbulence is included in the RNG mode enhancing the accuracy for swirling flows. 

Yu L, Lee LJ, Koelling KW (2004) Flow and heat transfer simulation of injection molding with microstructures. Poiym Eng Sci 44(10) 1866-1876... 

In order to provide some physical insight into the dynamics of microchannel heat sinks (MCHS), steady laminar water flow in a smooth single trapezoidal microchannel is discussed and compared with measured data sets. Then the effects of nanofluids on augmented MCHS heat transfer are introduced, employing very simple correlations for the enhanced thermal conductivities of the mixtures. The fluid flow and heat transfer simulations have been carried out with the commercial... 

BEM/low, Boundary Element Fluid and Heat Transfer Simulation Program, (c)1996. The Madison Group PPRC... 

In the simulation, the heat transfer between the coolant and solution is simplified as the heat transfer from the wall to the solution in the mixing tank. In order to maintain the solution temperature on a specific cooling curve during the batch, the wall temperature should be reset over time according to the process requirements. The variation of the wall temperature over time results in the variation of the solution temperature over time and in accordance with the location based on the heat transfer simulation. Based on the solution temperature distribution at the current time step, i, and at the last time step, i-1, the rate of transferred heat as well as the average temperature of the solution at the current time step i can be calculated. Furthermore, the heat transfer coefficient at the current time step, /, can be calculated using the rate of transferred heat and the temperature difference between the solution and the wall. The main equation for the calculation of heat transfer can be expressed as ... 

A very similar combined process scheme integrating OCM and steam reforming of methane (SRM) was suggested at the same time by Tiemersma et al [44]. OCM is performed in membrane reactor for distributed O2 feeding. The membrane reactor tubes are immersed into a fluidized-bed reforming reactor for optimal heat transfer. Simulation of such process based on kinetic data obtained... 

Saucedo-Castaneda, G., Guierrez Rojas, M., Bacquet, G., Raimbault, M., and Viniegra Gnzalez, G. (1990) Heat transfer simulation in solid substrate fermentation. Biotechnol Bioeng, 35, 802. 

The overall goal of this project is to develop a simphfied approach to predict the part temperature and to estimate a minimum safe eooling time using one dimensional heat transfer simulation and to establish rules or guidehnes as to how this approach can be applied to eomplieated parts. In this paper, we present the method and show eomparison to experimental result using simple and eomplex molds. 

---