Download or read book Investigation of Radiation and Conduction Heat Transfer in Fibrous High Temperature Insulations written by Edmund J. Rolinski and published by . This book was released on 1967 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: The experimental investigation was concerned with understanding the mechanisms by which fibrous insulations attenuate the transfer of thermal energy. Three fibrous insulation materials, Dynaquartz, Sapphire Wool, and Dynaflex, were evaluated for their usefulness in the high temperature environment. Effective thermal conductivities were measured in air, argon, and vacuum up to 2500 deg F. Transmission experiments were carried out to evaluate the relative contribution of radiation attenuation parameters for Dynaquartz.
Download or read book Investigation of the Thermal Properties of High temperature Insulation Materials written by A. E. Wechsler and published by . This book was released on 1963 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: This program encompasses an analytical and experimental investigation of the thermal properties of high temperature insulation materials. Effective thermal conductivities of graphite and zirconia fibers were measured in the temperature range of -320 to 200 F. The results were compared with empirical and theoretical models of heat transfer in fibrous insulations. Measurements of visible and infrared transmission through insulation materials indicated that scattering is the principal mechanism of radiation attenuation. Scattering and absorption cross sections estimated from the transmission data are given and show little effect of insulation temperature. The effective thermal conductivities of evacuated insulation systems were measured in the temperature range from 60 to 4000 F. The stability of materials exposed to high temperature vacuum environment for up to 170 hours was studied.
Download or read book Investigation of Heat Transfer in Fibrous Silica High Temperature Insulation written by Edmund Joseph Rolinski and published by . This book was released on 1966 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effective Thermal Conductivity of High Temperature Insulations for Reusable Launch Vehicles written by Kamran Daryabeigi and published by . This book was released on 1999 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling Effect of Microstructure on the Performance of Fibrous Heat Insulation written by Raghu Raja Simha Arambakam and published by . This book was released on 2013 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heat insulation is the process of blocking the transfer of thermal energy between objects at different temperatures. Heat transfer occurs due to conduction, convection, or radiation, as well as any combination of these three mechanisms. Fibrous insulations can completely suppress the convective mode of heat transfer for most applications, and also help to reduce the conductive and radiative modes to some extent. In this study, an attempt has been made to computationally predict the effects of microstructural parameters (e.g., fiber diameter, fiber orientation and porosity) on the insulation performance of fibrous materials. The flexible simulation method developed in this work can potentially be used to custom-design optimal multi-component fibrous insulation media for different applications. With regards to modeling conductive heat transfer, a computationally-feasible simulation method is developed that allows one to predict the effects of each microstructural parameter on the transfer of heat across a fibrous insulation. This was achieved by combining analytical calculations for conduction through interstitial fluid (e.g., air) with numerical simulations for conduction through fibrous structures. With regards to modeling radiative heat transfer, both Monte Carlo Ray Tracing and Electromagnetic Wave Theory were implemented for our simulations. The modeling methods developed in this work are flexible to allow simulating the performance of media made up of different combinations of fibers with different materials or dimensions at different operating temperatures. For example, our simulations demonstrate that fiber diameter plays an important role in blocking radiation heat transfer. In particular, it was shown that there exists an optimum fiber diameter for which maximum insulation against radiative transfer is achieved. The optimum fiber diameter is different for fibers made of different materials and also depends on the mean temperature of the media. The contributions of conduction and radiation heat transfer predicted using the above techniques are combined to define a total thermal resistance value for media with different microstructures. Such a capability can be of great interest for design and optimization of the overall performance of fibrous media for different applications.
Download or read book Heat Transfer in Fibrous Materials written by Claes G. Bankvall and published by . This book was released on 1972 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat Transmission Measurements in Thermal Insulations written by R. P. Tye and published by ASTM International. This book was released on 1979-12 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NBS Special Publication written by and published by . This book was released on 1968 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radiative Contribution to the Thermal Conductivity of Fibrous Insulations written by RMF Linford and published by . This book was released on 1974 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Design studies on the reuseable surface insulation (RSI) systems for the Space Shuttle require accurate data on the thermal conductivity of ceramic-fiber insulations. Well-established laboratory techniques, such as the guarded hot plate experiment, are available for such measurements; however, caution must be exercised in applying laboratory data to widely different re-entry thermal environments. The heat-transfer associated with infrared radiation transmitted through the fibrous materials must be considered. Various analytical models have been developed to account for this radiant heat transfer, but their verification has often been incomplete. A new approach has now been applied in which infrared transmission measurements were made with an optical system that collected all the scattered radiation transmitted through the back surface of fibrous samples. Experimental data were analyzed using a "two-flux" model for the radiation scattered and absorbed in the materials and excellent correlation was obtained between theory and experiment. To account for the wavelength dependence of the scattering cross-sections of many materials, a "four-flux" model was developed. This model was used to compute the contribution of the radiation transmission to the total thermal conductivity of samples measured on the guarded hot plate equipment. The contribution was shown to be as high as 75 percent of the total conductivity at temperatures above 1000 K.
Download or read book Radiation Heat Transfer in Fiber filled Silica Aerogel written by G. R. Cunnington and published by . This book was released on 1997 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Investigation of Thermal Insulating Materials for Undersea Habitats written by Lawrence B. Taylor and published by . This book was released on 1966 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Details and results of a literature search and study of thermal insulating materials for use at elevated pressures in atmospheres suitable for breathing are presented herein. Sufficient theory and data were found to permit determination of heat loss data of some insulating materials, assuming all the gas within the insulation was replaced by the breathing gas mixture. The accuracy of the theoretical values, the degree to which the gas mixture permeates the insulation, and the significance of the gas pressure in the permeation process remain to be determined experimentally. (Author).
Download or read book Heat Conduction and Mass Diffusion written by Benjamin Gebhart and published by McGraw-Hill Companies. This book was released on 1993 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt: Containing not only classical material and analysis, but using this as a basis for many kinds of application processes which are important in critical technologies, this text provides a comprehensive treatment of heat and mass transfer at graduate level.
Download or read book Thermal Transmission Measurements of Insulation written by Ronald Phillip Tye and published by ASTM International. This book was released on 1978 with total page 451 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Combined Conduction Radiation Heat Transfer and Mass Transfer in Fibrous Attic Insulations written by PW. Fairey and published by . This book was released on 1991 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: A numerical model to study heat transfer in an attic insulation has been developed. This model comprises combined conduction, radiation, and moisture transport. The one-dimensional energy equation, radiative transport equation and species equations for liquid H2O and vapor H2O were solved simultaneously. A control volume based finite difference method was used to solve the energy equation and the species equations. A quasi-analytical technique (method of discrete ordinates) was used in solving the radiative transport equation. Standard fiberglass insulations with and without a foil radiant barrier were modeled. Heat transfer results were compared with the experimental data measured at the Florida Solar Energy Center. Predicted heat fluxes agree with measured fluxes quite well. All the cases studied with moisture present were also studied for the dry cases (no mass transfer) and the results were compared. Results with moisture being included indicate that heat transfer from the attic into the house decreases for fiberglass insulations during summer as compared to dry insulation.
Download or read book Selected Advances in Insulation Technology written by United States. Small Business Administration. Technology Utilization Division and published by . This book was released on 1970 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Abstract Bulletin written by and published by . This book was released on with total page 818 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal Insulation Performance written by D. L. McElroy and published by ASTM International. This book was released on 1980 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt:
