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Stabilising dimensions of brass powder components

Wed, 01 Dec 2004 00:00:00 GMT

Title: Stabilising dimensions of brass powder components Authors: Ansari, Akhter H; Hameedullah, M; Asghar, M S J Abstract: Powder metallurgy components are manufactured by compacting metal powders. Hence, compaction pressure affects the properties of the components. In the present case, pre-alloyed cartridge brass (70:30) powder is employed for investigation and the effect of compaction pressure on dimensional properties of components is studied. A volumetric shrinkage is observed at various levels of compaction pressure. The shrinkage reduces with an increase in compaction pressure. It is 1.0% at 242 MPa, which reduces further to 0.4% at 725 MPa. At high level of compaction pressure, the shrinkage is found along the diameter. A swelling of 1.0% in diameter is exhibited at low level. Page(s): 481-486

Flow through S.I. engine air intake system using CFD at part throttle and full throttle

Thu, 01 Apr 2004 00:00:00 GMT

Title: Flow through S.I. engine air intake system using CFD at part throttle and full throttle Authors: Kumar, J Suresh; Ganesan, V Abstract: The objective of present study is to predict and analyze the flow through the SI engine air intake system using Computational Fluid Dynamics (CFD) and to validate the prediction by experimental data. Three-dimensional model of air intake system was analyzed by using the commercially available FLUENT software. The mesh was generated using the Tethybrid scheme which includes primarily of tetrahedral mesh elements but may include hexahedral, pyramidal and wedge elements. The pressure boundary conditions were used to define the fluid pressure at the inlet and outlet of Air Intake System. In the present study, the CFD code was validated by the experimental work. Experimental data was generated at one bar outlet pressure for the part throttle and full throttle conditions. The CFD plots give informative pictures of the flow field, which will help the designer to understand the effect of various components of Air Intake System. The predicted airflow rate shows good agreement with the experimental results. The results indicate that the CFD model can be used as a tool to understand the effect of various parts of air intake system for optimization. This in effect will reduce the number of experiments to be carried out for arriving at final optimized system. Page(s): 93-99

Investigation of the flow field in the various regions of intake manifold of a S.I. engine

Thu, 01 Apr 2004 00:00:00 GMT

Title: Investigation of the flow field in the various regions of intake manifold of a S.I. engine Authors: Kale, S C; Ganesan, V Abstract: The main objective of the present worlds to make a computational study of steady flow through intake manifold, port, valve and valve seat of a S.I. engine for various valve lifts. Three-dimensional flow within the manifold, port and valve has been simulated using the computational fluid dynamics (CFD) using the code STAR-CD. Flow field details in the identified regions in the manifold for the various valve lifts have been predicted. Analysis has been carried out for runners 1 and 3 at three different valve lifts for various speeds at wide-open throttle condition. A trimmed cell (adjust and cut process based on an underlying structured grid) has been adopted for meshing the geometries. Flow has been simulated by solving governing equations, viz., conservation of mass and momentum using the SIMPLE-algorithm. Turbulence has been modeled by high Reynolds number version of k-ɛ: model. Mass flow rate measurements have been made for validating the numerical prediction. A reasonably good agreement has been obtained between predicted and the experimental results. Also, it is seen that valve lift has a predominant effect on flow structure and it is found that with increase in valve lift there is a tendency for flow separation near the valve seat region. Page(s): 85-92

Analysis of reacting flows in an aero-engine afterburner using computational fluid dynamics

Sun, 01 Feb 2004 00:00:00 GMT

Title: Analysis of reacting flows in an aero-engine afterburner using computational fluid dynamics Authors: Unaune, Sunil V; Ganesan, V Abstract: In this paper, reacting flows in an aero-engine afterburner are analyzed using computational fluid dynamics (CFD). A computational procedure is described for calculating the three-dimensional reacting flow fields in a gas turbine afterburner. The computations are based on numerical solution of time-averaged transport equations for mass, momentum, turbulent kinetic energy and dissipation rate using a finite volume formulation. The numerical calculations are performed using SIMPLE(Semi Implicit Method for Pressure Linked Equations). The RNG (Re-normalization Group Theory) k-ɛ model is used for turbulence modeling. Combustion is modeled using PDF (Probability Density Function). The results for air-fuel Ratio of 30 and 46 are obtained and analyzed. Page(s): 31-37