scholarly journals Experimental investigation of structural and operational factor effects on speed performance of wave cleaving catamarans

2021 ◽  
pp. 13-19
Author(s):  
А.В. Сверчков ◽  
Г.Б. Крыжевич ◽  
А.Ю. Правдин
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Flow Resistance ◽  
Travel Speed ◽  
Rational Selection ◽  
Speed Performance ◽  
Operational Factor ◽  
Efficiency Effects ◽  
State Of Art ◽  
Selection Of

В статье приводятся результаты экспериментального исследования влияния конструктивных факторов на ходовые качества перспективного волнорассекающего пассажирского катамарана. Цель работы – поиск принципиальных технических решений по облику катамарана, обеспечивающих повышенные ходовые качества на тихой воде, в условиях волнения и экономическую эффективность. Оценено влияние скорости хода на ходовую посадку, гидродинамическое сопротивление, буксировочную и потребную мощность волнорассекающего катамарана. Выявлена эффективность применения транцевого интерцептора на волнорассекающем катамаране. Обсуждается рациональный выбор перемещения (выдвига) транцевого интерцептора при заданных значениях водоизмещения и эксплуатационной скорости. Выявлена целесообразность перехода от двулапых кронштейнов гребных валов к однолапым. Определено изменение потребной мощности при переходе от двулапого кронштейна к однолапому. Дана количественная оценка влияния выступающих частей (рулей и кронштейнов) на буксировочное сопротивление модели. Оценено взаимное влияние выдвига интерцептора и угла статического дифферента на характеристики ходкости при движении катамарана со скоростью экономического хода и эксплуатационной скоростью. Выявлена зависимость дополнительного буксировочного сопротивления модели на волнении от формы соединительного моста катамарана. Результаты исследований использованы при проектировании современного экологичного пассажирского катамарана проекта «Ecocruiser». The paper presents results of experimental study of structural factor effects on speed performance of a promising wave-cleaving passenger catamaran. The work purpose consists in searching for basic engineering solutions on the catamaran appearance that provide increased speed performance in still water and in seas, as well as economical efficiency. Effects of travel speed on operating trim, flow resistance, towrope power and power requirements of a wave-cleaving catamaran are evaluated. Effectiveness of using a transom intercepter in a wave-cleaving catamaran was identified. Rational selection of transom intercepter movement (advance) at specified displacement and operational speed values are discussed. Expedience of transition from two-leg propeller struts to single-leg ones is shown. Change of the power requirements at transition from two-leg propeller struts to single-leg ones is evaluated. Effects of projecting parts (rudders and propeller struts) on the model towrope resistance are evaluated quantitatively. Mutual effects of intercepter advance and static trim angle on the propulsion qualities under catamaran operation at economical and service speeds are evaluated. Dependence of the model additional towrope resistance in seas on the catamaran cross-deck structure shape are derived. The investigation results were used for design of a state-of-art ecological passenger catamaran “Ecocruiser”.

Rational selection of single oxide sorbents for syngas desulfurization regenerable at reduced temperature: Thermochemical calculations and experimental study

Fuel ◽  
2014 ◽  
Vol 128 ◽  
pp. 220-230 ◽  
Author(s):  
Vincent Girard ◽  
Arnaud Baudot ◽  
David Chiche ◽  
Delphine Bazer-Bachi ◽  
Christine Bounie ◽  
...  
Keyword(s):  
Experimental Study ◽  
Rational Selection ◽  
Reduced Temperature ◽  
Selection Of

An Experimental Investigation of the Efficacy of Lawyers' Letters

2002 ◽  
Vol 21 (1) ◽  
pp. 79-93 ◽  
Author(s):  
Jack L. Krogstad ◽  
Mark H. Taylor ◽  
Maribeth J. Stock
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Lower Bound ◽  
Financial Statements ◽  
Law Students ◽  
Potential Loss

This experimental study investigates the efficacy of lawyers' letters in providing auditors with corroborating evidence about litigation contingencies. Fifty second- and third-year law students indicate their willingness to provide auditors with estimates of the likelihoods of unfavorable outcomes and potential damages for two realistic litigation cases. The findings indicate that (1) the potential loss of attorney-client privilege and (2) likelihoods of unfavorable litigation outcomes that approach auditors' lower bound for accrual both may inhibit lawyers' responses to auditors. Overall, these findings raise doubts about the efficacy of this widely utilized auditing procedure and lead to concerns about whether litigation contingencies and corresponding losses may be underreported in financial statements.

scholarly journals The use of cement concrete pavements for roads, depending on climatic conditions

2019 ◽  
Vol 13 (3) ◽  
pp. 235-240
Author(s):  
Iryna Solonenko
Keyword(s):  
European Union ◽  
Statistical Models ◽  
Road Network ◽  
The European Union ◽  
Rational Selection ◽  
Cement Concrete ◽  
The Road ◽  
Road Pavement ◽  
Operational Characteristics ◽  
Selection Of

The development of road network infrastructure is an important component of the economic development of the European Union. Updating of the road network contributes to the integration of the economies of countries into a coherent whole. The road network provides the free movement of citizens, the movement of goods and the effective implementation of various services. The increase in the length of the road network leads to an increase in the financial and material costs necessary to ensure its maintenance and repair. One of the ways to reduce costs is by strengthening the physic-mechanical and operational characteristics of the pavement due to the widespread use of cement concrete. The quality of the pavement of cement concrete depends largely on the rational selection of its composition. This allows a significant increase in the durability of road pavement. The purpose of the research was: the development of recommendations for the rational selection of the composition of the road pavement material of cement concrete, aimed at upgrading longevity, and taking into account its frost resistance grade. According to the goal, the following tasks were developed: the analyses of the climatic zones in which the road network of the European Union is located; the development of a research plan, a selection of the response function and influence factors; the study of physico-mechanical and operational characteristics of the researched material of road pavement; on the basis of the obtained data, the calculation of the complex of experimental-statistical models, which describe the physico-mechanical and operational characteristics of the road pavement material; on the basis of experimental statistical models, a method was proposed for selecting the rational compositions of the cement concrete pavement road material depending on the conditions of its application. The results presented in the article can be used in engineering and scientific practice for the selection of road pavement from cement concrete for highways.

Experimental Investigation of Microcutting Mechanisms in Marble Grinding

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
LJ. Tanovic ◽  
P. Bojanic ◽  
R. Puzovic ◽  
S. Klimenko
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Cutting Force ◽  
Surface Finish ◽  
Normal Component ◽  
Natural Material ◽  
Grinding Process ◽  
Force Component ◽  
Diamond Grain

This paper offers an experimental study of the microcutting mechanisms in marble grinding to aid the optimization of the marble grinding process. The necessity for investigating these mechanisms is dictated by the increased use of marble in many applications and the fact that grinding and polishing processes are the dominant technologies used to meet surface finish requirements in this natural material. The experiments are aimed at the determination of the normal component of the cutting force and of the grain traces in microcutting with a single diamond grain. The investigations carried out make provisions for establishing critical grain penetration and cutting depths and allow the prediction of the normal cutting force component as a function of grain penetration speed and depth.

Experimental Study on Sand and Cement Replacement by Termite Mound Soil

2019 ◽  
pp. 279-287
Author(s):  
Harish R ◽  
Ramesh S ◽  
Tharani A ◽  
Mageshkumar P
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Compressive Strength ◽  
Natural Environment ◽  
Fine Aggregate ◽  
Test Results ◽  
Termite Mound ◽  
Cement Concrete ◽  
Cement Ratio ◽  
Compressive Strength Of Concrete

This paper presents the results of an experimental investigation of the compressive strength of concrete cubes containing termite mound soil. The specimens were cast using M20 grade of concrete. Two mix ratios for replacement of sand and cement are of 1:1.7:2.7 and 1:1.5:2.5 (cement: sand: aggregate) with water- cement ratio of 0.45 and varying combination of termite mound soil in equal amount ranging from 30% and 40% replacing fine aggregate (sand) and cement from 10%,15%,20% were used. A total of 27 cubes, 18 cylinders and 6 beams were cast by replacing fine aggregate, specimens were cured in water for 7,14 and 28 days. The test results showed that the compressive strength of the concrete cubes increases with age and decreases with increasing percentage replacement of cement and increases with increasing the replacement of sand with termite mound soil cured in water. The study concluded that termite mound cement concrete is adequate to use for construction purposes in natural environment.

Characterisation of the Femtosecond Laser Micro-Grooving Process for Germanium Substrates

2016 ◽  
Vol 874 ◽  
pp. 291-296 ◽  
Author(s):  
Lin Li ◽  
Jun Wang ◽  
Huai Zhong Li
Keyword(s):  
Experimental Study ◽  
Process Parameters ◽  
Material Removal ◽  
Removal Rate ◽  
High Quality ◽  
Scan Speed ◽  
Micro Grooving ◽  
Fs Laser ◽  
Selection Of ◽  
Germanium Substrates

An experimental study is reported to characterise the femtosecond (FS) laser grooving process for Germanium (Ge) substrates. The effects of process parameters, including laser fluence, pulse repetition rate and scan speed, on the groove characteristics, material removal rate (MRR) and heat affected zone (HAZ) size are discussed. It is shown that with properly selected process parameters, high quality micro-grooves can be obtained on Ge wafers. Recommendations are finally made on the selection of the most appropriate process parameters for FS micro-grooving of Ge substrates.

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