Author: Atanas TerziyskiPublisher:
ISBN:
Category :
Languages : en
Pages : 206
Book Description
Experimental and Modelling Studies of the Adsorption of Acetone on Ice Surfaces at Temperatures Around 200 K
Author: Atanas TerziyskiNumerical Methods and Applications
Author: Ivan DimovPublisher: Springer Science & Business Media
ISBN: 3642184650
Category : Computers
Languages : en
Pages : 524
Book Description
This book constitutes the thoroughly refereed post-conference proceedings of the 7th International Conference on Numerical Methods and Applications, NMA 2010, held in Borovets, Bulgaria, in August 2010. The 60 revised full papers presented together with 3 invited papers were carefully reviewed and selected from numerous submissions for inclusion in this book. The papers are organized in topical sections on Monte Carlo and quasi-Monte Carlo methods, environmental modeling, grid computing and applications, metaheuristics for optimization problems, and modeling and simulation of electrochemical processes.
Transport and Fate of Acetone in an Outdoor Model Stream, Stennis Space Center Near Bay St. Louis, Mississippi
Author: Studies of the Chemical Behavior of Small Molecules Adsorbed on Ice Surfaces
Author: Jason Eric SchaffDissertation Abstracts International
Author: Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 972
Book Description
Adsorption of Acetone on Bio-like Surfaces
Author: Ju-lu ChuPhysics Briefs
Author: Keywords Index to U.S. Government Technical Reports
Author: Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1160
Book Description
Ice Adhesion Strength Modeling Based on Surface Morphology Variations
Author: Taylor KnuthPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
A physics-based analytical model to predict the adhesion shear strength of impact ice on varying surface morphologies was developed and validated experimentally. The model focuses on the surface morphology effects on ice adhesion strength. As super-cooled water droplets, having a typical median volume diameter ranging from 10 to 80 [mu]m, impact and freeze on the leading edges of aircraft, it is hypothesized that the small drops expand and clamp to surface discontinuities, contributing to the ice adhesion strength of the material. The derivation of a Newtonian mechanics model to calculate the forces required for the removal of ice that has expanded and clamped inside macro surface structures is presented. The model requires knowledge of the macro-scale (10-6 m) surface geometry. Newtonian mechanics accounted for the expansion and clamping of freezing ice including temperature dependent ice properties. The model is dependent on Young's modulus, the thermal coefficient of expansion of ice, and the coefficient of static friction between ice and the adhering substrate. All of these properties are dependent on the variation of temperature. The research validated the developed model experimentally. Firstly, the individual parameters as functions of temperature were obtained from literature review and experimental measurements. Previous research revealed the correlation with temperature of the Young's modulus and the thermal coefficient of expansion for ice. The relationship for the thermal coefficient of expansion found is valid for temperatures ranging between -193.15 and 6.85 °C (-315.67 and 44.33 °F). The Young's modulus temperature relationship was obtained from tests presented in the literature that used sea ice. Secondly, the static coefficient of friction is dependent on the surface interaction between the accreted ice and the surface material. Through bench top testing, it was determined that the coefficient of friction of ice is also dependent on temperature. The coefficient of friction was experimentally acquired for a mercaptan and amine blended epoxy (Great Planes 30 Minute Pro Two-Part) applied to an aluminum substrate. The coefficient of friction varied from 0.046 with a standard deviation of 0.015 at -5.8 °C (21.6 °F) to 0.190 with a standard deviation of 0.019 at -15.7 °C (3.7 °F), a change of 420%, and is dependent on loading conditions and the test environment.The final phase of the research was the experimental validation of the ice adhesion model through adhesion strength testing on the Adverse Environment Rotor Test Stand (AERTS). To conduct validation testing, controlled surfaces were created. The surfaces were coated with the same mercaptan and amine epoxy blend to create a surface that approached a Ra of zero. The actual surface roughness measured was a Ra of 0.01 [mu]m (3.94 x 10-7 in.). This pristine coating provided a baseline against other surface of the same coating that had controlled surface roughness. The epoxy surfaces were ablated using a laser at differing intensities to create surfaces with varying roughness depths. The laser etched the coatings at 0.35, 0.6, and 1.2 W, each with a respective surface roughness of 1.13, 1.95, and 5.11 Ra (4.45 x 10-5, 7.68 x 10-5, and 2.01 x 10-4 in.). All of these coatings were tested within the Federal Aviation Regulation Part 25 and Part 29 Appendix C icing envelope to recreate realistic environmental icing conditions. The pristine surface was had an adhesion strength of 4.11 psi (28.3 kPa) with a standard deviation of 0.75 psi (5.17 kPa) at -8 °C (17.6 °F) and 7.99 psi (55.1 kPa) with a standard deviation of 0.94 psi (6.48 kPa) at -16 °C (3.2 °F). While, for example, the coating with the most severe ablation (Ra of 5.11 [mu]m) was had an adhesion strength of 22.7 psi (156.8 kPa) with a standard deviation of 2.70 psi (18.62 kPa) at -8 °C and 42.4 psi (292.5 kPa) with a standard deviation of 3.45 psi (23.79 kPa) at -16 °C. These measured values were then compared to the model predictions. The maximum discrepancy between prediction and experimental results was 9% for the 25 experimental tests conducted using the 1.2 W ablation surface.
Keywords Index to U.S. Government Technical Reports (permuted Title Index).
Author: United States. Department of Commerce. Office of Technical ServicesPublisher:
ISBN:
Category : Government publications
Languages : en
Pages : 860
Book Description