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Full-Text Articles in Engineering
Municipal Wastewater Reuse As Makeup To Cooling Towers, David Goldstein, John Casana, Irvine Wei
Municipal Wastewater Reuse As Makeup To Cooling Towers, David Goldstein, John Casana, Irvine Wei
Irvine W. Wei
At the first Water Reuse Symposium in March 1979 we presented a literature survey on the reuse of municipal wastewater as makeup to circulating cooling systems. We concluded that the wastewater was useable and not excessively costly. Since then we have corresponded with most of the plants in the world who are reusing water this way (we have received information from seven plants). About half the plants surveyed use extensive chlorination and half use no chlorination at all and encourage biological activity. No plants report problems with corrosion even when ammonia is present. The old problem of foam is dying …
A Study Of The Continous Cooling Behaviour And Effect Of Preheat And Interpass Temperature On The Haz Of High Strength Quenched And Tempered Steel, Lenka Kuzmikova, Mark Callaghan, Nathan Larkin, Robert Scott, Robert De Jong, Huijun Li, John Norrish
A Study Of The Continous Cooling Behaviour And Effect Of Preheat And Interpass Temperature On The Haz Of High Strength Quenched And Tempered Steel, Lenka Kuzmikova, Mark Callaghan, Nathan Larkin, Robert Scott, Robert De Jong, Huijun Li, John Norrish
Nathan Larkin
In this study, the continuous cooling phase transformation behaviour of a quenched and tempered armour steel was investigated. A continuous cooling transformation diagram was constructed providing valuable information for predicting microstructural evolution and mechanical properties at different cooling rates during actual welding fabrication. Welding trials were carried out utilising flux-cored arc welding technique in combination with an austenitic stainless steel consumable. The effect of various preheat and interpass temperatures on cooling rate and consequently on the heat affected zone microstructure and mechanical properties of multipass welds were investigated.
Effects Of Varying Cds Levels And Drying And Cooling Temperatures On Flowability Properties Of Ddgs, Rumela Bhadra, Kasiviswanathan Muthukumarappan, Kurt A. Rosentrater
Effects Of Varying Cds Levels And Drying And Cooling Temperatures On Flowability Properties Of Ddgs, Rumela Bhadra, Kasiviswanathan Muthukumarappan, Kurt A. Rosentrater
Kurt A. Rosentrater
Demand for alternative fuels and the need to reduce dependence on fossil fuels, have triggered the growth of corn-based ethanol production, and this is expected to rise in future years. Transportation of the co-product distillers dried grains with solubles (DDGS) from this industry occurs under various environmental conditions. It is often problematic, since caking between the particles can lead to flow problems. In this study we have prepared DDGS by combining condensed distillers solubles (CDS) with distillers wet grains (DWG) and then drying. We investigated the effects of CDS (10, 15, and 20% wb), drying temperature (100, 200, and 300°C), …
Thermionic Cooling Of Optoelectronic And Microelectronic Devices, S. P. Lee, B. C. Lough, R. A. Lewis, C. Zhang
Thermionic Cooling Of Optoelectronic And Microelectronic Devices, S. P. Lee, B. C. Lough, R. A. Lewis, C. Zhang
Chao Zhang
Solid-state thermionic cooling has gained attention recently because of its potential high cooling power. Thermionic devices based on semiconductor heterostructures utilize the band-edge offset at a heterojunction as the thermionic emission potential barrier and a thin layer to separate the cold and hot junction. In this paper, we present the behavior of thermionic coolers with periodic barriers using gallium arsenide/aluminium gallium arsenide (GaAs/Al/sub x/Ga/sub 1-x/As) semiconductor heterostructures. The exact numerical calculation to model the device performance has shown that the thermal efficiency in a multilayer structure is optimised when the effect of phonon scattering is introduced in the model. Besides, …
Unsteady Effects On Trailing Edge Cooling, G. Medic, Paul A. Durbin
Unsteady Effects On Trailing Edge Cooling, G. Medic, Paul A. Durbin
Paul A. Durbin
It is shown how natural and forced unsteadiness play a major role in turbine blade trailing edge cooling flows. Reynolds averaged simulations are presented for a surface jet in coflow, resembling the geometry of the pressure side breakout on a turbine blade. Steady computations show very effective cooling; however when natural-or even moreso, forced-unsteadiness is allowed, the adiabatic effectiveness decreases substantially. Streamwise vortices in the mean flow are found to be the cause of the increased heat transfer.
Toward Improved Film Cooling Prediction, G. Medic, Paul A. Durbin
Toward Improved Film Cooling Prediction, G. Medic, Paul A. Durbin
Paul A. Durbin
Computations of flow and heat transfer for a film-cooled high pressure gas turbine rotor blade geometry are presented with an assessment of several turbulence models. Details of flow and temperature field predictions in the vicinity of cooling holes are examined. It is demonstrated that good predictions can be obtained when spurious turbulence energy production by the turbulence model is prevented.
Liquid Immersion Cooling Of A Longitudinal Array Of Discrete Heat Sources In Protruding Substrates: Ii—Forced Convection Boiling, Theodore J. Heindel, S. Ramadhyani, F. P. Incropera
Liquid Immersion Cooling Of A Longitudinal Array Of Discrete Heat Sources In Protruding Substrates: Ii—Forced Convection Boiling, Theodore J. Heindel, S. Ramadhyani, F. P. Incropera
Theodore J. Heindel
Forced convection boiling experiments have been performed for an in-line 1 x 10 array of discrete heat sources, flush mounted to protruding substrates located on the bottom wall of a horizontal flow channel. FC-72, a dielectric fluorocarbon liquid, was used as the heat transfer fluid, and the experiments covered a range of flow velocities, degrees of fluid subcooling, and channel heights. The maximum heater-to-heater surface temperature variation was less than 2.5°C and was insensitive to channel height under conditions of fully developed nucleate boiling. Although the fluid velocity influenced the heat flux for partially developed nucleate boiling, its influence was …
Liquid Immersion Cooling Of A Longitudinal Array Of Discrete Heat Sources In Protruding Substrates: I—Single-Phase Convection, Theodore J. Heindel, F. P. Incropera, S. Ramadhyani
Liquid Immersion Cooling Of A Longitudinal Array Of Discrete Heat Sources In Protruding Substrates: I—Single-Phase Convection, Theodore J. Heindel, F. P. Incropera, S. Ramadhyani
Theodore J. Heindel
Experiments have been performed using water and FC-77 to investigate heat transfer from an in-line 1 x 10 array of discrete heat sources, flush mounted to protruding substrates located on the bottom wall of a horizontal flow channel. The data encompass flow regimes ranging from mixed convection to laminar and turbulent forced convection. Buoyancy-induced secondary flows enhanced heat transfer at downstream heater locations and provided heat transfer coefficients comparable to upstream values. Upstream heating extended enhancement on the downstream heaters to larger Reynolds numbers. Higher Prandtl number fluids also extended heat transfer enhancement to larger Reynolds numbers, while a reduction …