Computational equation discovery of relationships between container ship fuel consumption and hull and propeller fouling phenomena

Nowadays, when we try to automatize all activities, there is a growing demand for energy in all forms. Increasingly we reach for new energy sources that can be problematic to store or to transport, owing to their toxicity or explosive propensity. The article examines the issues of determining danger zones occurring as a result of liquefied natural gas (LNG) release. The range of danger zones caused through LNG release depends on a multitude of factors. The basic parameter that needs to be considered is a type of the released substance as well as the manner of its release. The range of a danger zone is determined by, inter alia, the concentration of a released substance and the atmospheric conditions existing at the time when depressurization occurs. The article analyses the problem of the range of danger zones in a function of wind speed and surface roughness with a defined value of Pasquill stability for various LNG types, starting with pure methane, and ending with the so-called LNG-heavy. The difficulty of the task becomes more complicated when the analysed surface over which a depressurization incident takes place involves water. The problem deepens even further when the analysed substance possesses explosive properties. Then, apart from regular substance concentration, upper and lower flammability limit ought to be considered. Calculations were conducted with DNV-Phast software, version 7.11.

Theoretical Calculation of Heat Losses of Heat Exchangers to Vicinity

This contribution is focused on heat exchangers and their heat losses dispersed into vicinity. In the introduction of the contribution this loss heat flow of heat exchangers is analysed into basic physical processes and with applying simplifying assumptions it is described by a computational equation suitable for technical practice. The result of the study is the confirmation of the general fact that the quotient of losses heat into vicinity with regard to the transferred heat flows in the heat exchanger is insignificant.

Fracture Behavior of Silicon Carbide Measured by Different Test Methods

Single edge notched beam (SENB) and indentation methods (IM) were used to test the fracture toughness (KIC) of SiC ceramic in present work. Both of testing results were compared. The applicative computational equation of indentation crack was determined through studying indentation morphology formed by IM. The results showed that the indentation crack in SiC could be Babcock crack, and the KIC value calculated by Niihara (P) indentation equation approximated to real value mostly with minimum relative deviation.