The Coatings Formation and Characteristic of a Low Pressure Thermal Plasma Torch

Compared with the atmosphere plasma spraying (APS), low pressure plasma spraying (LPPS) has been widely used due to deposit a specific and unique coating. A new low pressure thermal spraying plasma torch was designed according to the plasma spray characteristic in the low pressure environment. The plasma jet characteristic and the coatings microstructure were analyzed. In this study, Kundsen number has a great effect on the heat transfer of feedstock powder. With the increase of current, the plasma torch efficiency will decrease. A equiaxed microstructure of 316L coatings were deposited.

KARAKTERISTIK SPRAY BAHAN BAKAR CAMPURAN MINYAK DIESEL DAN BIODIESEL CALLOPHYLLUM INOPHYLLUM

The characteristic of spray largely determines of combustion quality. Before testing the fuel of diesel engine, characteristic of spray is needed to know. Biodiesel made from nyamplung seeds (callophyllum inophylum) mixed with diesel oil for spray characteristics test. The research was conducted at 1 atm ambient pressure, 15 MPa injection pressure. The fuel used Oil diesel added biodiesel variation B0, B20, B30, dan B100. The fuel mixture sprayed by nozzle tester and recorded using a 480 fps camera at 224x168 resolution to cognize spray tip penetration and spray angle. The result of research showing viscosity of fuel mixture has huge impact on spray characteristic. At high viscosity, longer spray tip penetration longer and smaller spray angle. Its affects the homogeneity of the mixture of fuel and the air. Keywords: spray characteristic, biodiesel, callophyllum inophylum

The Wide Fuel and its Characteristics

Water in diesel emulsion is an optional fuel, has a potential to reduce the formation of both nitrogen oxides, carbon dioxides and particulate matters in diesel engine. Thus the performance of this emulsified fuel strongly depends on the type of emulsion, stability of emulsion, amount of surfactant and the physio-chemical properties. In this study, water in diesel emulsion fuels of 5%, 10%, 20%, 25% water by volume was prepared by a mechanical stirrer. Physical and chemical properties of emulsion were examined as this properties could influence the spray characteristic of the emulsion which can affect the ignition delay and flame propagation, the carbon contents for emulsified fuel with 10% and 20% were low droplet size of the emulsion was found to be less than 2 µm. The water content in the emulsified fuel also include the amount of surfactant density and viscosity was found to be higher for all of the water in diesel emulsion the pure diesel.

Numerical Analysis of Nozzle Flow and Spray Characteristics from Different Nozzles Using Diesel and Biofuel Blends

In this paper, the discrete phase model (DPM) was introduced to study the fuel injector cavitations process and the macro spray characteristic of three different types of nozzle spray shape with diesel and hybrid biofuel blend for several injection pressures and backpressures. The three types of nozzle spray shapes used were circle, elliptical A type, and elliptical B type. The cavitations’ flows inside the injector nozzles were simulated with Computer Fluid Dynamics (CFD) simulations using the cavitations mixture approach. The effect of nozzle spray shape towards the spray characteristic of hybrid biofuel blends is analyzed and compared with the standard diesel. Furthermore, a verification and validation from both the experimental results and numerical results are also presented. The nozzle flow simulation results indicated that the fuel type did not affect the cavitation area vastly, but were more dependent on the nozzle spray shape. In addition, the spray width of the elliptical nozzle shape was higher as compared to the circular spray. Moreover, as the backpressure increased, the spray width downstream increased as well. The spray tip penetration for the elliptical nozzle shape was shorter than the circular nozzle shape due to circular nozzles having smaller nozzle widths and lesser spray cone angles. Thus, this resulted in smaller aerodynamic drag.