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  • 1
    Call number: ZSP-201-76/12
    In: CRREL Report, 76-12
    Description / Table of Contents: The heat transfer processes associated with melting and refreezing a drill hole 500 m in depth and 0.150 m in initial radius through an ice shelf were approximately analyzed. The results were expressed in graphical form showing the time available for experimentation under the hole as a function of heating duration and heating strength. It was found that the refreezing of the drill hole had a much slower rate than the melting of the hole.
    Type of Medium: Series available for loan
    Pages: vi, 15 Seiten , Illustrationen
    Series Statement: CRREL Report 76-12
    Language: English
    Note: Contents Abstract Preface Summary Nomenclature Introduction Analysis Melting period Freezing period Calculation Conclusion Literature cited Appendix A: Justification of using eq 8 for the calculation of heat transfer coefficient h
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  • 2
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    Hanover, NH : U. S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-88/14
    In: CRREL Report, 88-14
    Description / Table of Contents: An experimental study covering a mass flow rate ranging from 1.62 to 67.45 g/cm2-s and snow density varying from 0.377 to 0.472 g/cm3 has been conducted. Pressure drops ranging from 0.012 to 2.868 gf/cm2 were recorded. A plot of the friction factor fp vs Rep (defined as the classical Reynolds number Re for fluid flow through conduits) showed a good representation of all the experimental data. The least-squares analysis resulted in an expression of f sub p = 118/Rep to the 1.095 power for snow, in comparison with the expression f sub p = 64/Rep developed for fluid flow through porous media of randomly packed metallic and nonmetallic materials of spherical and nonspherical shapes.
    Type of Medium: Series available for loan
    Pages: iv, 18 Seiten , Illustrationen
    Series Statement: CRREL Report 88-14
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Experimental setup and procedure Experimental results Discussion and conclusions Literature cited
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  • 3
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    Hanover, NH : U. S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-87/19
    In: CRREL Report, 87-19
    Description / Table of Contents: The approximate heat balance integral method (HBIM) is extended to the case of a medium with variable properties such as snow. The case of linear variation of thermal conductivity was investigated. An alternative heat balance integral method (AHBIM) was developed. Both constant surface temperature and surface heat flux were considered. A comparison was made of the temperature distribution from the HBIM, AHBIM and an analytical method for the case of constant surface temperature. In general, results agree quite well with the analytical method for small values of dimensionless time τ, but the difference becomes more pronounced as τ increases. It was found that the AHBIM with a quadratic temperature profile gave a somewhat better result, especially when the value of the dimensionless distance η is small. For a specific property function of E(η) = eη, closed form solutions were obtained. The results, when compared with those from HBIM, AHBIM and the analytical method were found to agree exceptionally well with the analytical method, especially for large values of τ.
    Type of Medium: Series available for loan
    Pages: iv, 26 Seiten , Illustrationen
    Series Statement: CRREL Report 87-19
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Mathematical analysis Constant surface temperature Constant surface heat flux Comparison with exact solution Alternative method Conclusions and comments Literature cited Appendix A: Derivation of equation 25 Appendix B: Derivations of equations 37 and 40 Appendix C: Derivation of equations 37a and 40
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  • 4
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-81/10
    In: CRREL Report, 81-10
    Description / Table of Contents: Abstract: This treatise thoroughly reviews the subjects of density, thermal expansion and compressibility of ice; snow density change attributed to destructive, constructive and melt metamorphism; and the physics of regelation and the effects on penetration rate of both the thermal properties of the wire and stress level. Heat capacity, latent heat of fusion and thermal conductivity of ice and snow over a wide range of temperatures were analyzed with regression techniques. In the case of snow, the effect of density was also evaluated. The contribution of vapor diffusion to heat transfer through snow under both natural and forced convective conditions was assessed. Expressions representing specific and latent heat of sea ice in terms of sea ice salinity and temperature were given. Theoretical models were given that can predict the thermal conductivities of fresh bubbly ice and sea ice in terms of salinity, temperature and fractional air content.
    Type of Medium: Series available for loan
    Pages: 27 Seiten , Illustrationen
    Series Statement: CRREL Report 81-10
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Density, thermal expansion and compressibility of ice Density Thermal expansion Compressibility Density changes in snow Compaction Destructive metamorphism Constructive metamorphism Melt metamorphism Regelation Thermal properties of snow and fresh-water ice Heat capacity of snow and ice Latent heat Thermal conductivity of ice Thermal conductivity of snow Effective thermal diffusivity Heat transfer by water vapor diffusion in snow Heat and vapor transfer with forced convection Thermal properties of sea ice Specific heat of sea ice Heat of fusion of sea ice when 0° 〉 θ 〉 -8.2°C Density and thermal conductivity of sea ice Composition and air bubble content of sea ice above -8.2°C Thermal conductivity model for sea ice Thermal diffusivity of sea ice Method of determining thermal diffusivity Summary Literature cited
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  • 5
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    Hanover, NH : Corps of Engineers, U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-335
    In: Research report
    Description / Table of Contents: CONTENTS: Abstract. - Preface. - Ňomenclature. - Introduction. - Experimental apparatus and procedure. - Testspecimens. - Bubble frequency and velocity. - Analysis of experimental results. - Discussion. - Summary. - Literature cited.
    Description / Table of Contents: An experimental study of the heat transfer characteristics of a bubble-driven water jet on an ice surface was conducted. Two Lucite columns, one 1.829 m high and 0.286 m in diameter and the other 1.219 m high and 0.140 m in diameter were used. Water levels were maintained at 0.762 and 1.524 m in the large column and 0.840 m in the small column. Hypodermic needles with openings of 0.152, 0.406 and 0.838 mm were used for bubble formation. The air flow rate was varied from 7.39 X 10^-8 to 9.91 X I0^-7 m^3/s. In all, 171 experimental runs were conducted. The results can be correlated by Nu = 0.1735 (Rei)^0.848 with a correlation coefficient of 0.84, in which Nu is defined in terms of average heat transfer coefficient h, sample diameter Ds, and thermal conductivity of water kw. Rei is defined in terms of diameter of the impinging water jet at the ice surface, Di, the centerline arrival water velocity vc and the kinematic viscosity of water uw.
    Type of Medium: Series available for loan
    Pages: vi, 16 S. : graph. Darst.
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory, CRREL, US Army Material Command 335
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  • 6
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    Hanover, NH : U.S. Army Materiel Command, Terrestrial Sciences Center, Cold Regions Research & Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-263
    In: Research report
    Description / Table of Contents: CONTENTS: Preface. - Abstract. - Introduction. - Theoretical background. - Experimental apparatus and procedures. - Results and discussion. - Conclusions. - Literature cited.
    Description / Table of Contents: The transition in the mode of heat transfer from conduction to convection in a layer of water formed continuously by melting ice from below has been determined experimentally. This was accomplished by locating the inflection point on the curve relating the water-ice interface (or melting front) and time. Thus, the critical Rayleigh number, Rac, at which convective heat transfer started can be correlated empirically as a function of warm plate temperature, Ts, by Rac= 14,200 exp(-6.64 x 10^-2 Ts). This relation is valid for Ts varying from 7.72 to 25.50°C. The initial ice temperature T0 was varied from -4.8 to -22.00°C. The effect of T0 was found to be insignificant. Homogeneous, bubble-free ice was prepared and used in all the experiments.
    Type of Medium: Series available for loan
    Pages: iv, 12 S. : Ill.
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory, CRREL, US Army Material Command 263
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  • 7
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-84/6
    In: CRREL Report, 84-6
    Description / Table of Contents: An expression relating aerosol growth to cold environmental conditions was developed. This was accomplished by solving the diffusion equation with the method of Laplace transformation. The series solution was expressed in terms of the dimensionless parameters K (ratio of vapor density over droplet surface to droplet density), ω (ratio of environmental vapor density at time zero to vapor density over droplet surface), and dimensionless time τ (ratio of product of diffusion coefficient D and time t to square of initial radius of condensation nucleus). To take into account the variation of the vapor density over the surface of an acidic condensation nucleus due to the continuous dilution of the droplet, the solution was obtained by assuming various levels of constant vapor concentration. The final expression [R/R sub o - 1 = 2.4917 x 10 to the minus 18th power) exp(0.0737 θ) (P sub RHS/25) x (100-P sub RHS) τ to the 0.9890 powder] can be used to compute the value of R once the values of initial radius R sub o, relative humidity P sub RH, percent of relative humidity at the droplet surface P sub RHS, and environmental temperature θ are given.
    Type of Medium: Series available for loan
    Pages: vi, 28 Seiten , Illustrationen
    Series Statement: CRREL Report 84-6
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature General background The problem Method of solution Results and discussion Conclusions Literature cited Appendix: Evaluation of rn's in equation 25
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  • 8
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    Hanover, NH : U. S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-87/22
    In: CRREL Report, 87-22
    Description / Table of Contents: This review discusses problems associated with the anomalous temperature-density relations of water. It covers a) onset of convection, b) temperature structure and natural convective heat transfer, and c) laminar forced convective heat transfer in the water/ice system. The onset of convection in a water/ice system was found to dependent on thermal boundary conditions, not a constant value as in the classical fluids that have a monotonic temperature-density relationship. The water/ice system also exhibits a unique temperature distribution in the melt layer immediately after the critical Rayleigh number is exceeded and soon after it establishes a more or less constant temperature region progressively deepening as the melt layer grows. The constant temperature is approximately 3.2°C for water layers formed from above but varies for melt layers from below. The heat flux across the water/ice interface was found to be a weak power function and to increase linearly with temperature for melted layers from above and below, respectively.
    Type of Medium: Series available for loan
    Pages: vi, 43 Seiten , Illustrationen
    Series Statement: CRREL Report 87-22
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Analytical studies on the onset of convection in a horizontal water layer Experimental studies on the onset of convection in a circular horizontal melt layer Temperature structure and heat transfer In a horizontal layer In a circular horizontal melt layer pHeat transfer studies in nonplanar geometries Forced convective heat transfer over a melting surface Discussion and conclusions Onset of convection Temperature structure and natural convective heat transfer Laminar forced convective heat transfer Literature cited
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  • 9
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-103
    In: Research report / Cold Regions Research and Engineering Laboratory, 103
    Description / Table of Contents: Summary: The effect of air flow on the thermal conductivity of snow was investigated. Steady-state temperature measurements were made along the edge and axis of a cylindrical bed of snow to determine the effective axial thermal conductivity of snow. Unconsolidated snow samples were used, with densities ranging from 0.376 to 0.472 g/cm^3 and corresponding snow particle sizes of 0.065 to 0.219 cm nominal diameter; the mass flow rates employed ranged from approximately 10-40 x 10^-4g/cm^2 sec. Snow density and sample size apparently have opposite effects on the effective thermal conductivity because of the flow of fluid in snow. The test apparatus is described in detail and is illustrated. The results of the experiments are tabulated, and a least square equation is given which represents the results well.
    Type of Medium: Series available for loan
    Pages: iv, 14, A2 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 103
    Language: English
    Note: CONTENTS Preface Summary Introduction Theory Apparatus and experimental procedure Results and discussion References Appendix A: Sample calculations of a and ke
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  • 10
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-106
    In: Research report / Cold Regions Research and Engineering Laboratory, 106
    Description / Table of Contents: From the Preface: This paper presents a method for determining the extent of heat transfer due to vapor transfer in snow with air flowing through it, which could be useful in connection with studies concerning the changes of physical and mechanical properties of a snow cover caused by temperature gradients and wind currents.
    Type of Medium: Series available for loan
    Pages: iv, 8, A2, B2, C4 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 106
    Language: English
    Note: CONTENTS Summary Introduction Theory Experimental apparatus apd procedures Results and discussion References Appendix A: Evaluation of d^2Ps/dx^2, dps/dx Appendix B: Sample calculations of β0, β, and De Appendix C: Experimental results and calculated data
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