scholarly journals Selected aspects of application of dual fuel marine engines

2012 ◽  
Vol 148 (1) ◽  
pp. 25-34
Author(s):  
Tomasz KNIAZIEWICZ ◽  
Leszek PIASECZNY
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Liquid Fuels ◽  
Dual Fuel ◽  
Fuel Gas ◽  
Simulation Research ◽  
Marine Engine ◽  
Marine Engines ◽  
Dual Fuel Engines ◽  
Marine Vessels

The paper presents examples of application of dual fuel marine engines based on the expertise of the largest marine engine manufacturers. The fueling systems of these engines have been presented as fueled with fuel gases in various combinations with liquid fuels. Examples of the application of dual fuel engines in vessels as well as variants of the powertrains have been shown. The results of own simulation research (Monte Carlo method) have also been presented related to the NOx emission from a variety of vessels operating in the area of the Bay of Gdansk proving that the use of engines fueled with fuel gas may indeed reduce the emission of NOx from marine vessels operating in this area.

Optimization of High Pressure Direct Injection Micro-Pilot As a Retrofit Technology for Conventional Dual Fuel Engines

2019 ◽  
Author(s):  
Greg Beshouri ◽  
Gerry Fischer
Keyword(s):  
High Pressure ◽  
Performance Optimization ◽  
Experimental Testing ◽  
Direct Injection ◽  
Dual Fuel ◽  
Injection Timing ◽  
Test Results ◽  
Fuel Gas ◽  
Single Cylinder ◽  
Dual Fuel Engines

Abstract In the late 1980’s Enterprise Engine Company performed a single cylinder test of micro-pilot high pressure direct injection as a retrofit technology for conventional dual fuel engines. While that testing demonstrated a number of benefits for this technology, non-technical considerations led to the use of low pressure Pre-Combustion Chamber (PCC) micro-pilot technology as the retrofit technology instead. Thirty years later, when the automotive components of the PCC micro-pilot system were no longer available, the opportunity again arose to test the capabilities of an off the shelf high pressure direct injection micro-pilot system as a retrofit technology for a conventional dual fuel engine. Single cylinder and full engine testing of the high pressure direct injection micro-pilot injection confirmed the results of the 1980’s testing. The test results also corroborated modern analytical and experimental testing of high pressure pilot technology. In particular, the interaction between the diesel pilot and primary fuel gas charge is very complex and sometimes counterintuitive. Likewise performance optimization requires careful balance of injection timing, injection quantity and fuel gas air/fuel ratio. Even then, exhaust gas methane emissions remain counterintuitive. This paper reviews modern single cylinder and full engine test results focusing on optimization parameters for high pressure direct injection micro-pilot for retrofit and new engine applications.

Simulation and Analysis for Damage of Certain Electrical Power Equipment in Battlefield

2014 ◽  
Vol 989-994 ◽  
pp. 1141-1145
Author(s):  
Xin Yu Yang ◽  
Qi Shuang Ma ◽  
Pei Yuan Cheng ◽  
Qiang Zhang ◽  
Lin Zhang
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Power Unit ◽  
Electrical Power ◽  
Electrical Equipment ◽  
Technical Support ◽  
Power Equipment ◽  
Simulation Research ◽  
Simulation Procedure

For the need of simulation research of technical support and obtain basic rush repair data of certain ground-to-air electrical equipment in battlefield condition, this paper studies on the simulation for damage of certain electrical power equipment in battlefield. It analyzes threat mechanisms and basic damage theories of power unit and compiles simulation procedure adopting Monte Carlo method. By simulation, it can analyze vulnerability and distributing of damage parts for electrical power equipment. All this provides reference for rush repair and instruct to defend in battlefield condition.

scholarly journals New Optimization of ME-GI Dual Fuel Engines for LNG Carriers and Marine Vessels in General

2009 ◽  
Vol 44 (6) ◽  
pp. 876-887
Author(s):  
Kjeld Aabo ◽  
Rene Sejer Laursen
Keyword(s):  
Dual Fuel ◽  
Dual Fuel Engines ◽  
Marine Vessels

scholarly journals An Approach for Predicting the Specific Fuel Consumption of Dual-Fuel Two-Stroke Marine Engines

2019 ◽  
Vol 7 (2) ◽  
pp. 20 ◽  
Author(s):  
Crístofer Marques ◽  
Jean-D. Caprace ◽  
Carlos Belchior ◽  
Alberto Martini
Keyword(s):  
Programming Languages ◽  
Fuel Consumption ◽  
Simulation Models ◽  
Specific Fuel Consumption ◽  
Dual Fuel ◽  
Marine Fuel ◽  
Proposed Model ◽  
Marine Engines ◽  
Dual Fuel Engines ◽  
Selection Of

Increasing environmental demands, alongside the planned penetration of natural gas as marine fuel, have rendered dual-fuel engines as an attractive prime mover alternative. In this context, knowing the specific fuel consumption is essential to selecting the most efficient engine. The specific fuel consumption can be approached by simulation models with varying levels of complexity that are either implemented by basic programming languages or simulated by dedicated packages. This study aims to develop a simplified model to predict the specific fuel consumption of dual-fuel two-stroke marine engines driving fixed or controllable pitch propellers. The model relies on clear trends approachable by polynomials that were revealed by normalizing specific fuel consumption. This model requires only the value of specific fuel consumption at a nominal maximum continuous rating to predict the engine consumption at any specified rating, including at partial engine load. The outcome of the study shows that the maximum deviations regarding the two simulated engines did not exceed −3.6%. In summary, the proposed model is a fast and effective tool for optimizing the selection of dual-fuel, two-stroke Diesel engines regarding fuel consumption.

Outbursts of comet Schwassmann-Wachmann 1, and the cloud of interplanetary boulders

1974 ◽  
Vol 22 ◽  
pp. 307 ◽  
Author(s):  
Zdenek Sekanina
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Interplanetary Space ◽  
Porous Matrix ◽  
Maximum Diameter ◽  
Expansion Velocity ◽  
Solid Constituent ◽  
Meteoric Material ◽  
Periodic Comet

AbstractIt is suggested that the outbursts of Periodic Comet Schwassmann-Wachmann 1 are triggered by impacts of interplanetary boulders on the surface of the comet’s nucleus. The existence of a cloud of such boulders in interplanetary space was predicted by Harwit (1967). We have used the hypothesis to calculate the characteristics of the outbursts – such as their mean rate, optically important dimensions of ejected debris, expansion velocity of the ejecta, maximum diameter of the expanding cloud before it fades out, and the magnitude of the accompanying orbital impulse – and found them reasonably consistent with observations, if the solid constituent of the comet is assumed in the form of a porous matrix of lowstrength meteoric material. A Monte Carlo method was applied to simulate the distributions of impacts, their directions and impact velocities.

Structures and crystallization of vacuum-deposited amorphous Se and Sb films

1990 ◽  
Vol 48 (4) ◽  
pp. 140-141
Author(s):  
Makoto Shiojiri ◽  
Toshiyuki Isshiki ◽  
Tetsuya Fudaba ◽  
Yoshihiro Hirota
Keyword(s):  
Monte Carlo ◽  
Electron Microscope ◽  
Monte Carlo Method ◽  
Computer Program ◽  
Radial Distribution ◽  
Film Formation ◽  
Amorphous State ◽  
Two Dimensional ◽  
Amorphous Films ◽  
Binding Condition

In hexagonal Se crystal each atom is covalently bound to two others to form an endless spiral chain, and in Sb crystal each atom to three others to form an extended puckered sheet. Such chains and sheets may be regarded as one- and two- dimensional molecules, respectively. In this paper we investigate the structures in amorphous state of these elements and the crystallization.HRTEM and ED images of vacuum-deposited amorphous Se and Sb films were taken with a JEM-200CX electron microscope (Cs=1.2 mm). The structure models of amorphous films were constructed on a computer by Monte Carlo method. Generated atoms were subsequently deposited on a space of 2 nm×2 nm as they fulfiled the binding condition, to form a film 5 nm thick (Fig. 1a-1c). An improvement on a previous computer program has been made as to realize the actual film formation. Radial distribution fuction (RDF) curves, ED intensities and HRTEM images for the constructed structure models were calculated, and compared with the observed ones.

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