19,365 Matching Results

Search Results

Advanced search parameters have been applied.

Measurements of Recovery Factors and Coefficients of Heat Transfer in a Tube for Subsonic Flow of Air

Description: Note presenting measurements of heat flow to air at subsonic velocities and substantially constant Reynolds number, which show that the heat-transfer coefficient is independent of the difference between the temperature of the heated wall and the adiabatic wall temperature. Recovery factors are measured at the pipe wall for adiabatic flow.
Date: June 1945
Creator: McAdams, William H.; Nicolai, Lloyd A. & Keenan, Joseph H.
Partner: UNT Libraries Government Documents Department

An Investigation of Aircraft Heaters 3: Measured and Predicted Performance of Double Tube Heat Exchangers

Description: Report presenting a study of two double tube cylindrical heat exchangers, in which hot exhaust gases pass through the annular space and ventilating air passes through the center tube, to determine heat transfer performance and pressure drop. Tests were performed in order to establish a simple, accurate method of predicting the performance of the double tube heat exchanger, to compare the performance of the straight and dimpled tubes, and to determine the pressure drop across the units.
Date: October 1942
Creator: Martinelli, R. C.; Weinberg, E. B.; Morrin, E. H. & Boelter, L. M. K.
Partner: UNT Libraries Government Documents Department

Experimental investigation of air-side performance of liquid-metal to air heat exhangers

Description: Report describing an experiment to obtain heat-transfer and pressure-drop data for the air side of a liquid-metal to air, shell-and-tube heat exchanger. Testing was conducted in a 500 kilowatt facility using sodium as the shell-side heating fluid. Results regarding the shell-and-tube heat exchanger and finned-tube heat exchanger friction factor are provided.
Date: March 16, 1956
Creator: Gedeon, Louis; Conant, Charles W. & Kaufman, Samuel J.
Partner: UNT Libraries Government Documents Department

An investigation of aircraft heaters 20: measured and predicted performance of a finned-type cast-aluminum crossflow exhaust gas and air heat exchanger

Description: Report presenting data on the thermal performance and static pressure drop of a finned-type cast-aluminum exhaust gas and air heat exchanger. Results regarding heat transfer, isothermal pressure drop, and heater surface temperature are provided.
Date: April 1945
Creator: Boelter, L. M. K.; Guibert, A. G.; Rademacher, J. M.; Romie, F. E. & Sanders, V. D.
Partner: UNT Libraries Government Documents Department

Method of calculating core dimensions of crossflow heat exchanger with prescribed gas flows and inlet and exit states

Description: Report presenting a calculation procedure by which the dimensions of the core of a gas-to-gas crossflow heat exchanger with prescribed heat-transfer surface can be determined rapidly. The procedure is based on a number of charts that may be prepared for each surface with prescribed entrance conditions, pressure drops, and temperature changes.
Date: April 1956
Creator: Eckert, E. R. G. & Diaguila, Anthony J.
Partner: UNT Libraries Government Documents Department

Forced-convection heat-transfer and pressure-drop characteristics of a closely spaced wire matrix

Description: Memorandum presenting an investigation of the forced-convection heat-transfer and pressure-drop characteristics of a staggered closely spaced 0.020-inch wire metal-to-air heat exchanger. Eight wire banks were electrically heated, and the range of variables included bulk Reynolds numbers based on wire diameter and maximum velocity, from 82 to 1900, average wire temperatures up to 1109 degrees R, and heat flux densities up to 84,000 Btu per hour per square foot.
Date: August 13, 1954
Creator: Gedeon, Louis & Grele, Milton D.
Partner: UNT Libraries Government Documents Department

Waste Heat Recovery Fluids for Heavy-Duty Transportation Bottoming Cycle Systems : A Summary Report

Description: Working fluids used in Rankine bottoming cycle systems for heat recovery from long-haul trucks, marine vessels, and railroad locomotives are examined. Rankine bottoming cycle systems improve fuel economy by converting the exhaust heat from the prime mover into useful power. The report assesses fluid property requirements on the basis of previous experience with bottoming cycle systems. Also, the exhaust gas characteristics for the transportation modes of interest are summarized and compared. Candidate working fluids are discussed with respect to their potential for use in Rankine bottoming cycle systems. Analytical techniques are presented for calculating the thermodynamic properties of single-component working fluids. The resulting equations have been incorporated into a computer code for predicting the performance of Rankine bottoming cycle systems. In evaluating candidate working fluids, the code requires the user to input only a minimal amount of fluid property data.
Date: September 1983
Creator: Krazinski, J. L.; Uherka, K. L.; Holtz, Robert E. & Ash, J. E.
Partner: UNT Libraries Government Documents Department

Plastic Heat Exchangers : A State-of-the-Art Review

Description: Significant increases in energy utilization efficiency can be achieved through the recovery of low-temperature rejected heat. This energy conserving possibility provides incentive for the development of heat exchangers which could be employed in applications where conventional units cannot be used. Some unique anticorrosion and nonstick characteristics of plastics make this material very attractive for heat recovery where condensation, especially sulfuric acid, and fouling occur. Some of the unique characteristics of plastics led to the commercial success of DuPont's heat exchangers utilizing polytetrafluoroethylene (trade name Teflon) tubes. Attributes which were exploited in this application were the extreme chemical inertness of the material and its flexibility, which enabled utilization in odd-shaped spaces. The wide variety of polymeric materials available ensures chemical inertness for almost any application. Lower cost, compoundability with fillers to improve thermal/mechanical properties, and versatile fabrication methods are incentives for many uses. Also, since many plastics resist corrosion, they can be employed in lower temperature applications (< 436 K), where condensation can occur and metal units have been unable to function. It is clear that if application and design can be merged to produce a cost-effective alternate to present methods of handling low-temperature rejected heat, then there is significant incentive for plastic heat exchangers, to replace traditional metallic heat exchangers or to be used in services where metals are totally unsuited.
Date: July 1979
Creator: Miller, David; Holtz, Robert E.; Koopman, R. Nelson; Marciniak, Thomas J. & MacFarlane, Donald R.
Partner: UNT Libraries Government Documents Department

Heat-Related Illnesses

Description: "This indicator tracks how often people are hospitalized because of exposure to heat."
Date: August 2016
Creator: United States. Environmental Protection Agency.
Partner: UNT Libraries Government Documents Department

Boiling Heat Transfer of Refrigerant R-113 in a Small-Diameter, Horizontal Tube

Description: Results of a study of boiling heat transfer from refrigerant R-113 in a small-diameter (2.92-mm) tube are reported. Local heat transfer coefficients over a range of heat fluxes, mass fluxes, and equilibrium mass qualities were measured. The measured coefficients were used to evaluate eight different heat transfer correlations, some of which have been developed specifically for refrigerants. High heat fluxes and low flow rates are inherent in small channels, and this combination results in high boiling numbers. The high boiling number of the collected data shows that the nucleation mechanism was dominant. As a result, the two-phase correlations that predicted this dominance also predicted the data best if they also properly modeled the physical parameters. The correlations of Lazarek and Black and of Shah, as modified in this study, predicted the data very well. It is also shown that a simple form, suggested by Stephan and Abdelsalam for nucleate boiling, correlates the data equally well. This study is part of a research program in multiphase flow and heat transfer, with the overall objective of developing validated design correlations and predictive methods that will facilitate the design and optimization of compact heat exchangers for use with environmentally acceptable alternatives for chlorofluorocarbon (CFC) refrigerants and refrigerant mixtures.
Date: January 1992
Creator: Wambsganss, M. W.; France, D. M.; Jendrzejczyk, J. A. & Tran, T. N.
Partner: UNT Libraries Government Documents Department

Forced-Convection Heat Transfer to Water at High Pressures and Temperatures in the Nonboiling Region

Description: "Forced-convection heat-transfer data have been obtained for water flowing in an electrically heated tube of circular cross section at water pressures of 200 and 2000 pounds per square inch, and temperatures in the nonboiling region, for water velocities ranging between 5 and 25 feet per second. The results indicate that conventional correlations can be used to predict heat-transfer coefficients for water at pressures up to 2000 pounds per square inch and temperatures in the nonboiling region" (p. 1).
Date: November 29, 1951
Creator: Kaufman, S. J. & Henderson, R. W.
Partner: UNT Libraries Government Documents Department

An investigation of aircraft heaters 17: experimental inquiry into steady state unidirectional heat-meter corrections

Description: Report divided into two sections. One discusses a correction that must be applied to a heat meter when it is used at temperatures other than temperatures at which it was calibrated. The other section contains the results of an application of the two methods of correcting the heat-transfer rates for contact and heat-meter resistance to experimental data.
Date: August 1944
Creator: Boelter, L. M. K.; Poppendiek, H. F. & Gier, J. T.
Partner: UNT Libraries Government Documents Department

An investigation of aircraft heaters 24: the heat meter in the transient state for unidirectional heat transfer

Description: Report describing the behavior of the heat meter when it is used in thermal circuits which are under the influence of transient potentials. Three scenarios are considered: a heat meter suddenly placed on a hot surface, a heat meter mounted on the interior surface of the cabin wall of an uninsulated airplane climbing through air of decreasing temperature, and a heat meter mounted on the interior surface of the composite cabin wall of an airplane climbing through air of decreasing temperature.
Date: September 1944
Creator: Boelter, L. M. K.; Poppendiek, H. F.; Dunkle, R. V. & Gier, J. T.
Partner: UNT Libraries Government Documents Department

Sodium Reactor Experiment Power Expansion Program: Heat Transfer Systems Modifications

Description: Abstract: Under the Power Expansion Program (PEP), modifications have been made to the Sodium Reactor Experiment (SRE) facility to improve plant reliability and permit an increase in power to 30 Mwt, with a reactor coolant outlet temperature up to 1200°F.
Date: October 9, 1964
Creator: Freede, W. J. & Roberts, J. K.
Partner: UNT Libraries Government Documents Department

Preliminary Results of Heat Transfer from a Stationary and Rotating Ellipsoidal Spinner

Description: "Convective heat-transfer coefficients in dry air were obtained for an ellipsoidal spinner of 30-inch maximum diameter for both stationary and rotating operation over a range of conditions including airspeeds up to 275 miles per hour, rotational speeds up to 1200 rpm, and angles of attack of zero and 4 degrees. The results are presented in terms of Nusselt numbers, Reynolds numbers, and convective heat-transfer coefficients. The studies included both uniform heating densities over the spinner and uniform surface temperatures" (p. 1).
Date: August 6, 1953
Creator: von Glahn, U.
Partner: UNT Libraries Government Documents Department

Transient Temperature in Infinite Plates, Infinite Cylinders, and Spheres Following a Simultaneous Step Change in Internal Heat Generation Rate, Coolant Temperature and Heat Transfer Coefficient

Description: Report regarding the problem of transient temperature in infinite plates, infinite cylinders, and spheres following during convective cooling after heat generation.
Date: 1958
Creator: Epel, Lester G.
Partner: UNT Libraries Government Documents Department

Heat Treatment and Properties of Iron and Steel

Description: From Abstract: "This Monograph has been prepared to give an understanding of heat treatment principally to those unacquainted with this subject. This Monograph has been prepared to answer such inquiries and to give in simplified form a working knowledge of the basic theoretical and practical principles involved in the heat treatment of iron and steel."
Date: October 3, 1960
Creator: Digges, Thomas G. & Rosenberg, Samuel J.
Partner: UNT Libraries Government Documents Department

Heat Treatment and Properties of Iron and Steel

Description: From Abstract: "This Monograph is a revision of the previous NBS Monograph 18. Its purpose is to provide an understanding of the heat treatment of iron and steels, principally to those unacquainted with this subject. The basic principles involved in the heat treatment of these materials are presented in simple form." From Introduction: "This Monograph has been prepared to answer such inquires and to give in simplified form a working knowledge of the basic theoretical and practical principles involved in the heat treatment of iron and steel."
Date: November 1, 1966
Creator: Digges, Thomas G.; Rosenberg, Samuel J. & Geil, Glenn W.
Partner: UNT Libraries Government Documents Department

Vapor Compression with Secondary Heat-Transfer Media

Description: From Introduction: "The use of a secondary heat-transfer media in a vapor-compression distillation unit was suggested for investigation as a process for saline water conversion because previous studies on the vapor-compression cycle at low temperatures showed that the fixed charges on the compressor are a substantial part of the final water-product cast. Other fluids were evaluated as above, the results of which are shown in table 1. Data on the other fluids shown in table 1 will be found in the appendix."
Date: December 1961
Creator: H.K. Ferguson Company
Partner: UNT Libraries Government Documents Department

Research on Thermoelectric Heat Pumps

Description: From Results: "Prior to stating results achieved, let us first discuss the measurements we were able to make, and how these measurements might--or might not--be indicative of the objective we strove to reach. Tables I and II, and related Figs. 11 and 12, show the best results obtained. Final Columns of Tables I and II are believed to show, at least to a degree, how good or how poor our best sputtered films turned out to be, compared with top-quality Peliter semiconductor materials."
Date: November 1963
Creator: Cox, E. F.
Partner: UNT Libraries Government Documents Department