scholarly journals Ship Resistance When Operating in Floating Ice Floes: A Derivation of Empirical Equations

2021 ◽  
Author(s):  
Luofeng Huang ◽  
Zhiyuan Li ◽  
Christopher Ryan ◽  
Minghao Li ◽  
Jonas Ringsberg ◽  
...  
Keyword(s):  
Empirical Equations ◽  
Ship Resistance ◽  
Ice Floes

scholarly journals Ship Resistance When Operating in Floating Ice Floes: A Derivation of Empirical Equations

2020 ◽  
Author(s):  
Luofeng Huang ◽  
Christopher Ryan ◽  
Bojan Igrec ◽  
Andrea Grech La Rosa ◽  
Dimitris Stagonas ◽  
...  
Keyword(s):  
The Arctic ◽  
Empirical Equations ◽  
Ship Resistance ◽  
Open Sea ◽  
Ice Concentration ◽  
Arctic Shipping ◽  
Ice Floes ◽  
Ship Performance ◽  
Propulsion Power ◽  
Ship Speed

Abstract With the effects of global warming, the Arctic is presenting a new environment where numerous ice floes are floating on the open sea surface. Whilst this has unprecedentedly improved Arctic shipping navigability and brought about significant opportunities, the interaction of such floes with ships has yet to be understood, thus hindering appropriate assessment of corresponding ship performance. This paper presents work on developing empirical equations to estimate the effects of such floes on ship resistance. Based on extensive data from validated computational simulations, the ice-floe resistance has been shown to correlate with ship beam, ship speed, ice concentration, ice thickness and floe diameter, and the regression powers of each the parameter on resistance are ascertained for a container ship. This leads to an empirical equation that can immediately predict ice-floe resistance in a given condition. The proposed approach has the potential to facilitate propulsion power estimates for Arctic shipping, as well as providing valuable insights into ship design for these environmental conditions.

scholarly journals Ship resistance when operating in floating ice floes: A combined CFD&DEM approach

2020 ◽  
Vol 74 ◽  
pp. 102817 ◽  
Author(s):  
Luofeng Huang ◽  
Jukka Tuhkuri ◽  
Bojan Igrec ◽  
Minghao Li ◽  
Dimitris Stagonas ◽  
...  
Keyword(s):  
Ship Resistance ◽  
Ice Floes

Ship resistance when operating in floating ice floes: Derivation, validation, and application of an empirical equation

2021 ◽  
Vol 79 ◽  
pp. 103057
Author(s):  
Luofeng Huang ◽  
Zhiyuan Li ◽  
Christopher Ryan ◽  
Jonas W. Ringsberg ◽  
Blanca Pena ◽  
...  
Keyword(s):  
Empirical Equation ◽  
Ship Resistance ◽  
Ice Floes

Experimental study of ship resistance in artificial ice floes

2020 ◽  
Vol 176 ◽  
pp. 103102 ◽  
Author(s):  
Z. Zong ◽  
B.Y. Yang ◽  
Z. Sun ◽  
G.Y. Zhang
Keyword(s):  
Experimental Study ◽  
Ship Resistance ◽  
Ice Floes

Ship Resistance and Propulsion

2017 ◽  
Author(s):  
Anthony F. Molland ◽  
Stephen R. Turnock ◽  
Dominic A. Hudson
Keyword(s):  
Ship Resistance

Substituent effects in 1,3-indanediones

1982 ◽  
Vol 47 (5) ◽  
pp. 1486-1493 ◽  
Author(s):  
Alexander Perjéssy
Keyword(s):  
Substituent Effects ◽  
Empirical Equations ◽  
Substituent Constants ◽  
Complex Structural

The carbonyl stretching frequencies correlate well with substituent constants in a series of 166 1,3-indanediones using improved and extended Seth-Paul-Van Duyse equation. Transmissive factors and group electronegativities have been used to find empirical equations for calculation of substituent constants of more complex structural fragments.

Viscosity, electrical conductivity and density of the system ammonium nitrate-dimethyl sulphoxide

1984 ◽  
Vol 49 (5) ◽  
pp. 1109-1115
Author(s):  
Jindřich Novák ◽  
Zdeněk Kodejš ◽  
Ivo Sláma
Keyword(s):  
Electrical Conductivity ◽  
Aqueous Solutions ◽  
Ammonium Nitrate ◽  
Transport Properties ◽  
Calcium Nitrate ◽  
Dimethyl Sulphoxide ◽  
Present System ◽  
Empirical Equations ◽  
Concentrated Solutions ◽  
Nitrate Solutions

The density, viscosity, and electrical conductivity of highly concentrated solutions of ammonium nitrate in dimethyl sulphoxide have been determined over the temperature range 10-60 °C and the concentration range 7-50 mol% of the salt. The variations in the quantities as a function of temperature and concentration have been correlated by empirical equations. A comparison is made between the transport properties for the present system, aqueous solutions of ammonium nitrate, and calcium nitrate solutions in dimethyl sulphoxide.

scholarly journals Energy dissipation efficiency as a new variable in the empirical correlation of total dissolved gas

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jingying Lu ◽  
Xiaolong Cheng ◽  
Zhenhua Wang ◽  
Ran Li ◽  
Jingjie Feng ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Standard Error ◽  
Air Entrainment ◽  
Empirical Equations ◽  
Generation Process ◽  
Field Observations ◽  
Dissolved Gas ◽  
Total Dissolved Gas ◽  
Future Work ◽  
Hydropower Stations

AbstractTotal dissolved gas (TDG) supersaturation, which occurs during dam spilling, may result in fish bubble disease and mortality. Many studies have been conducted to identify the factors pertaining to TDG generation, such as the spilling discharge and tailwater depth. Additionally, the energy dissipation efficiency should be considered due to its effect on the air entrainment, which influences the TDG generation process. According to the TDG field observations of 49 cases at Dagangshan and Xiluodu hydropower stations, the TDG was positively related to the energy dissipation efficiency, tailwater depth and discharge per unit width. A correlation between the generated TDG level and these factors was established. The empirical equations proposed by the USACE were calibrated, and the TDG level estimation performance was compared with the established correlation for 25 spillage cases at seven other dams. Among the considered cases, the standard error of the TDG estimation considering the energy dissipation efficiency was 5.7%, and those for the correlations obtained using the USACE equations were 13.0% and 10.0%. The findings indicated that the energy dissipation efficiency considerably influenced the TDG level, and its consideration helped enhance the precision of the TDG estimation. Finally, the generality of this approach and future work were discussed.

scholarly journals A process-based method for predicting lateral erosion rates

2021 ◽  
Author(s):  
Myron van Damme
Keyword(s):  
Soil Mechanics ◽  
High Surface ◽  
Shear Stresses ◽  
Empirical Equations ◽  
Predictive Capability ◽  
Surface Shear ◽  
Erosion Rates ◽  
Material Texture ◽  
Empirical Coefficients ◽  
The Impact

AbstractAn accurate means of predicting erosion rates is essential to improve the predictive capability of breach models. During breach growth, erosion rates are often determined with empirical equations. The predictive capability of empirical equations is governed by the range for which they have been validated and the accuracy with which empirical coefficients can be established. Most empirical equations thereby do not account for the impact of material texture, moisture content, and compaction energy on the erosion rates. The method presented in this paper acknowledges the impact of these parameters by accounting for the process of dilation during erosion. The paper shows how, given high surface shear stresses, the erosion rate can be quantified by applying the principles of soil mechanics. Key is thereby to identify that stress balance situation for which the dilatency induced inflow gives a maximum averaged shear resistance. The effectiveness of the model in predicting erosion rates is indicated by means of three validation test cases. A sensitivity analysis of the method is also provided to show that the predictions lie within the range of inaccuracy of the input parameters.

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