Fluid flow and heat transfer

Abe, K., Kondoh, T., Nagano, Y. A new turbulence model for predicting fluid flow and heat transfer in separating and reattaching flows 1. Flow field calculations. Int. ]. Heat Mass Trans, fer, vol. 37, pp. 139-151, 1994. 

In addition to impurities, other factors such as fluid flow and heat transfer often exert an important influence in practice. Fluid flow accentuates the effects of impurities by increasing their rate of transport to the corroding surface and may in some cases hinder the formation of (or even remove) protective films, e.g. nickel in HF. In conditions of heat transfer the rate of corrosion is more likely to be governed by the effective temperature of the metal surface than by that of the solution. When the metal is hotter than the acidic solution corrosion is likely to be greater than that experienced by a similar combination under isothermal conditions. The increase in corrosion that may arise through the heat transfer effect can be particularly serious with any metal or alloy that owes its corrosion resistance to passivity, since it appears that passivity breaks down rather suddenly above a critical temperature, which, however, in turn depends on the composition and concentration of the acid. If the breakdown of passivity is only partial, pitting may develop or corrosion may become localised at hot spots if, however, passivity fails completely, more or less uniform corrosion is likely to occur. 

M6. Matzner, B., Basic experimental studies of boiling fluid flow and heat transfer at elevated pressures, TID 12574, Columbia Univ. (1961). 

Clearly, the maximum degree of simplification of the problem is achieved by using the greatest possible number of fundamentals since each yields a simultaneous equation of its own. In certain problems, force may be used as a fundamental in addition to mass, length, and time, provided that at no stage in the problem is force defined in terms of mass and acceleration. In heat transfer problems, temperature is usually an additional fundamental, and heat can also be used as a fundamental provided it is not defined in terms of mass and temperature and provided that the equivalence of mechanical and thermal energy is not utilised. Considerable experience is needed in the proper use of dimensional analysis, and its application in a number of areas of fluid flow and heat transfer is seen in the relevant chapters of this Volume. 

Experimental and numerical study of the pressure drop and heat transfer in a single-phase micro-channel heat sink by Qu and Mudawar (2002a,b) demonstrated that the conventional Navier-Stokes and energy equations can adequately predict the fluid flow and heat transfer characteristics. 

Chaudhari AM, Woudenberg TM, Albin M, Goodson KE (1998) Transient liquid crystal thermometry of microfabricated PCR vessel arrays. J Microelectromech Sys 7 345-355 Cheng P, Wu WY (2006) Mesoscale and microscale phase heat transfer. In Greene G, Cho Y, Hartnett J, Bar-Cohen A (eds) Advances in heat transfer, vol 39. Elsevier, Amsterdam Choi SB, Barron RF, Warrington RQ (1991) Fluid flow and heat transfer in micro- tubes. ASME DSC 40 89-93... 

Yoo JY (2006) Recent studies on fluid flow and heat transfer in thermal microdevices. Nanoscale Microscale Thermophys Eng 10 67-81... 

Yu DL, Warrington RO, Barron RE, Ameel T (1995) An experimental and theoretical investigation of fluid flow and heat transfer in micro-tubes. ASME/JSME Thermal Eng Conf 1 523-530... 

Choi SB, Barron R, Warrington RQ (1991) Fluid flow and heat transfer in micro-tubes. In Choi D et al. (eds) Micro-mechamcal sensors, actuators and systems. ASME DSC 32 121-128... 

Logtenberg, S. A., Nijemeisland, M., and Dixon, A. G., Computational fluid dynamics simulations of fluid flow and heat transfer at the wall-particle contact points in a fixed-bed reactor, Chem. Eng. Sci. 54, 2433-2439 (1999). 

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... 

Kried, D. K.,J. M.Creer,J. M. Bates, M. S. Quigley, A. M. Sutey, and D. S. Rowe, 1979, Fluid Flow Measurements in Rod Bundles Using Laser Doppler Anemometry Techniques, Fluid Flow and Heat Transfer over Rod or Tube Bundles, p. 13, ASME Winter Annual Meeting, ASME, New York. (3) Kudryavtsev, A. P., D. M. Ovechkin, D. N. Sorokin, V. I. Subbotin, and A. A. Tsyganok, 1967, Transfer... 

Our initial work on reaction thermal effects involved CFD simulations of fluid flow and heat transfer with temperature-dependent heat sinks inside spherical particles. These mimicked the heat effects caused by the endothermic steam reforming reaction. The steep activity profiles in the catalyst particles were approximated by a step change from full to zero activity at a point 5% of the sphere radius into the pellet. 

Peterson, J. and Y. Bayazitoglu. Optimization of Cost Subject to Uncertainty Constraints in Experimental Fluid Flow and Heat Transfer. J Heat Transfer 113 314-320 (1991). 

Karwe, M. V. and Jaluria, Y., Numerical Simulation of Fluid Flow and Heat Transfer in a Single-Screw Extruder for Non-Newtonian Fluids, Numer. Heat Transfer, Part A, 17, 167 (1990)... 

The advection—diffusion equation with a source term can be solved by CFD algorithms in general. Patankar provided an excellent introduction to numerical fluid flow and heat transfer. Oran and Boris discussed numerical solutions of diffusion—convection problems with chemical reactions. Since fuel cells feature an aspect ratio of the order of 100, 0(100), the upwind scheme for the flow-field solution is applicable and proves to be very effective. Unstructured meshes are commonly employed in commercial CFD codes. 

The actual vapor heat pump cycle deviates from the ideal cycle primarily because of inefficiency of the compressor, pressure drops associated with fluid flow and heat transfer to or from the surroundings. The vapor entering the compressor must be superheated slightly rather than a saturated vapor. The refrigerant entering the throttling valve is usually compressed liquid rather than a saturated liquid. 

PRUESS, K. 2002. Mathematical Modeling of Fluid Flow and Heat Transfer in Geothermal Systems. An introduction in five lectures held at the United Nations University Geothermal Programme, Reykjavik, Iceland. Report to the Earth Science Division, Lawrence Berkeley National Laboratory, University of California, 83 pp. 

S. Syrjala, On the Analysis of Fluid Flow and Heat Transfer in the Melt Conveying Section of a Single Screw Extruder, Num. Heat Trans., Part A, 35, 25-4-1 (1999). 

I. Fluid flow and heat transfer (thermal) equipment/processes, including solar energy systems (151 to 207). 

I. Applications of Second Law Analysis to the Design, Evaluation and Optimization of Fluid Flow and Heat Transfer (Thermal) Equipment/Processes, Including Solar Energy Systems... 

BASIC Programs for Steam Plant Engineers Boilers, Combustion, Fluid Flow, and Heat Transfer, V. Ganapathy... 

Recent inventions in micro and nano-scale systems and the development of micro and nano-scale devices continues to pose new challenges, and the understanding of the fluid flow and heat transfer at such scales is becoming more and more important. In Chapter 6, microscale heat transfer is presented as a Topic of Special Interest. 

In fluid flow and heat transfer studies, the ratio of dynamic viscosity to density appears frequently. For convenience, this ratio is given the name kinematic viscosity v and is expressed as v = filp. Two common units of kinematic viscosity are m /s and stoke (1 stoke = 1 cm /s = 0.0001 mVs). 

As we have discussed earlier, the buoyancy force is caused by the density difference between the healed (or cooled) fluid adjacent to the surface and tiie fluid surrounding it, and is proportional to this density difference and the volume occupied by the warmer fluid. It is also well knowu ll at whenever Iwc bodies in contact (.solid--solid, solid-fluid, or fluid-fluid) move relative to cacf other, a friction force develops at the contact surface in the direction opposite ic that of the motion. This opposing force slows down the fluid and thus reduce the flow rate of the fluid. Under steady conditions, the airflow rate driven b buoyancy is established at the point where these two effects balance each othet The friction force increases as more and more solid surfaces are introduced, se tiously disrupting the fluid flow and heat transfer. For that reason, heat sink with closely spaced fins are not suitable for natural convection cooling. 

This is a transient fluid flow and heat transfer problem. Figure 9 illustrates the growth of these layers adjacent to the wall as seen from a coordinate system traveling with the blade. 

J. H. Kim, Heat transfer in longitudinal laminar flow along circular cylinders in a square array. Fluid Flow and Heat Transfer over Rod or Tube Bundles (S.C. Yao and P.A. Pfund, eds.), Winter annual meeting of the American Society of Mechanical Engineers, December 2-7, New York, 1979, p. 155. 

Therefore, there is still a need for further research for a fundamental understanding of fluid flow and heat transfer phenomena in microchaimels in order to explore and control the phenomena in a length scale regime in which we have very little experience. 

Weisberg et al. [54] are among other researchers who all provided additional information and considerable evidence that the behavior of fluid flow and heat transfer in microchannels or microtubes without phase change is substantially different from that which occurs in large channels and/or tubes. 

Kavehpour et al. [20] solved the compressible two-dimensional fluid flow and heat transfer characteristics of a gas flowing between two parallel plates under both uniform temperature and uniform heat flux boundary conditions. They compared their results with the experimental results of Arkilic [3] for Helium in a 52.25x1.33x7500 mm channel. They observed an increase in the entrance length and a decrease in the Nusselt number... 

Toh et al. [45] investigated numerically three-dimensional fluid flow and heat transfer phenomena inside heated microchannels. The steady, laminar flow and heat transfer equations were solved using a finite-volume method. The numerical procedure was validated by comparing the predicted local thermal resistances with available experimental data. The friction factor was also predicted in this study. It was found that the heat input lowers the frictional losses, particularly at lower Reynolds numbers. Also, at lower Reynolds numbers the temperature of the water increases, leading to a decrease in the viscosity and hence smaller frictional losses. 

Choi, S.B., Barron R.F. and Warrington R.O., Fluid Flow and Heat Transfer in Microtubes, Micromechanical Sensors, Actuators, and Systems, ASME DSC-32, 1991, 123-134. 

Rahman, M.M. and Gui, F., Experimental Measurements of Fluid Flow and Heat Transfer in MicroChannel Cooling Passages in A Chip Substrate, Advances in Electronic Packaging, ASME EEP-4-2, 1993, 685-692. 

---