Impact of Jatropha Oil on Engine Performance, Emission Characteristics, Deposit Formation, and Lubricating Oil Degradation

Self Cite

Alternative fuels need to satisfy the strict requirements of the use for diesel engines aiming at enhancing the performance and reducing pollutant emissions. The use of straight bio-oils for diesel engines entails improving their disadvantages such as high density, high surface tension and kinematic viscosity (tri-physical parameters). There have been some as-used methods for reduction of the above-mentioned negative effects related to straight bio-oil disadvantage, however, the adequately-heating method may be considered as a simple one helping the physical parameters of straight bio-oils to reach stable and highly-confident values which are close to those of traditional diesel fuel. As a consequence, the spray and atomization, combustion, performance, and emissions of diesel engines fueled with preheated bio-oils are improved. In this work, a study of the dependence of the density, surface tension and kinematic viscosity of coconut oil (a type of bio-oils) on temperatures (from 40-110 o C) within a wide variety are conducted. In the first stage, the influence study of temperature on tri-physical parameters is carried out on the basis of experimental correlation and asdescribed mathematical equation. In the second stage, the influence study of tri-physical parameters on spray and atomization parameters including penetration length (L b) and Sauter mean diameter (SMD), and the influence of tri-physical parameters on fuel supply system are investigated. The optimal range of temperature for the as-used bio-oils is found after analyzing and evaluating the obtained results regarding the physical properties and spray characteristics, as well as compared with those of diesel fuel. The confident level over 95% from the regression correlation equation between the above-mentioned tri-physical parameters and temperature is presented. Additionally, the measured spray parameters, the calculated values of frictional head loss and fuel flow rate are thoroughly reported.

Section: Influence Of Vegetable Oil Physical Properties On Spray Cmentioning

confidence: 99%

Influences of heating temperatures on physical properties, spray characteristics of bio-oils and fuel supply system of a conventional diesel engine

Hoang

Pham²

2018

Self Cite

“…Also, longer penetration and smaller cone angle due to higher viscosity and density are the main causes resulting in reducing the total heated area of fuels because of the decrease in heat flux to fuel droplets. As reported, unburnt fuel is considered as the origination of deposits and lubrication oil degradation [34]. Because of those reasons, vegetable oils are suggested not being used for diesel engines in long-term.…”

Section: Spray Characteristicsmentioning

confidence: 99%

Experimental Analysis on the Ultrasound-based Mixing Technique Applied to Ultra-low Sulphur Diesel and Bio-oils

Hoang

Tran

2019

Self Cite

Pollution in the maritime field is considered as such a serious problem that scientists, policymakers, and managers are always urged with a desire to find solutions and strategies one way or another to minimize its negative impacts on the environment and the life. Among the effective solutions, the use of fuels with limited-sulfur content or bio-based fuels has been paid much attention to due to their advantages in the use of marine diesel engines. In the current study, a type of fossil diesel fuel with ultra-low sulfur content (ULSD) was mixed with coconut oil (CO) through the ultrasonic treatment under the changes in volume fraction of as-used fuels, the correlation on viscosity selected the rate mixing between ULSD and coconut oil. After 12 minutes of ultrasound treatment, the highest stability of the ULSD-CO emulsion was achieved correspondingly to 97.8% for a mixing rate of 76%(ULSD):24%(CO) along with the distance of 85mm from the containing-vessel bottom to the ultrasound horn tip. Moreover, the spray characteristics including penetration length and a cone angle of ULSD, CO, and ULSD-CO emulsion were also examined and compared to diesel fuel. The similarity of spray characteristics to diesel fuel, containing ultra-low sulfur content and oxygen content, renewability are considered as some advantages of ULSD-CO emulsion as used for diesel engines aiming to meet the stricter requirements of IMO regulations about the strategies of environmental protection.

“…The resistance prediction is one of the important problems in the ship design process and is also the basis of solving several critical practical problems such as calculating the main engine power and propeller under the hull, optimizing of the hull form to achieve the minimum resistance results. Up to now, in addition to traditional ship model test in towing tank, Computational Fluid Dynamics (CFD) has widely used to predict resistance and resolve complex problems in ship hydrodynamics [1], in which the flow around a hull is usually governed and computed with socalled Navier-Stokes equations that applied for the dynamics of Newtonian fluids [2], [3]. However, these equations cannot be solved in the turbulent case so when turbulences are important or significant, a modified form of Navier-Stokes equations in which the quantities dependent on time and space will be calculated according to their average quantities that are independent of time and space should be used [4].…”

Section: Introductionmentioning

confidence: 99%

Improving the Accuracy of Ship Resistance Prediction Using Computational Fluid Dynamics Tool

Huynh

Tran

2020

The ship resistance prediction using CFD tool has become an accepted method over the last decade; however, the CFDbased ship resistance results are not always accurate. This paper presents the approach of determining the input parameters of the CFD solution for ship resistance prediction, including of size and boundary conditions of the computational domain, and parameters of turbulent model in accordance with the geometric characteristics of hull to improve the accuracy of CFD-based resistance values for a specific ship type. Two same type of fishing vessels named FAO 72 and FAO 75 which are tested in towing tank are chosen as the computed ship to apply this approach for resistance prediction accurately. The CFD-based resistance results of these vessels are compared with corresponding model testing results to analyze accuracy and reliability of this approach as well as discussing the effect of the initial parameters of the CFD solution on the resistance results as mentioned. The research results shown that the accuracy of three dimensions (3D) model of computational ship, the appropriate values of computational domain size and turbulent model parameters for resistance prediction using CFD are the input factor to improve the accuracy of resistance values. Especially the specific values of computational domain size and turbulent model parameters are presented in this paper will be the input parameters to predict the resistance using CFD for the fishing vessels with the same geometric characteristics as the computed ship.