Showing papers by "Matthew Stickland published in 2009"

Rapid manufacturing technique used in the development of a regenerative pump impeller

Abstract: This paper presents a method of rapid manufacture used in the development of a regenerative pump impeller. Rapid manufacturing technology was used to create complex impeller blade profiles for testing as part of a regenerative pump optimisation process. Regenerative pumps are the subject of increased interest in industry. Ten modified impeller blade profiles, from the standard radial configuration, were evaluated with the use of computational fluid dynamics and experimental testing. Prototype impellers were needed for experimental validation of the CFD results. The manufacture of the complex blade profiles using conventional milling techniques is a considerable challenge for skilled machinists. The complexity of the modified blade profiles would normally necessitate the use of expensive CNC machining with 5 axis capability. With an impeller less than 75 mm in diameter and a maximum blade thickness of 1.3mm, a rapid manufacturing technique enabled production of complex blade profiles that were dimensionally accurate and structurally robust enough for testing. As more advanced rapid prototyping machines become available in the study in the future, e.g. 3D photopolymer jetting machine, the quality of the parts particularly in terms of surface finish will improve and the amount of post processing operations will reduce. This technique offers the possibility to produce components of increased complexity whilst ensuring quality, strength, performance and speed of manufacture. The ability to manufacture complex blade profiles that are robust enough for testing, in a rapid and cost effective manner is proving essential in the overall design optimisation process for the pump.

An investigation into unsteady base bleed for drag reduction in bluff two-box SUVs

Abstract: This paper discusses a preliminary investigation into the use of base bleed on a production SUV using CFD analysis. The paper shows the methods used in creating the computational model and conducting the analysis, and present the findings to date. The paper shows that the reduction in drag increases as the mass flow rate of air is increased when the flow is deflected at the outlet. By controlling the turbulent wake to the rear of the vehicle, it is shown in the paper that mass flow rates of under 2kg/s can reduce drag coefficient by 8.2% with an outlet on the side of the vehicle, and that a mass flow rate of under 1.5kg/s can reduce the drag coefficient by 10.7% for an outlet on the upper section of the rear of the vehicle. The paper also discusses the feasibility of base bleed being applied to a production vehicle.

Study of a regenerative pump using numerical and experimental techniques

Abstract: Regenerative pumps are the subject of increased interest in industry as these pumps are low cost, low specific speed, compact and able to deliver high heads with stable performance characteristics. The complex flow-field within the pump represents a considerable challenge to detailed mathematical modelling as there is significant flow separation in the impeller blading. This paper presents the use of a commercial CFD code to simulate the flow within the regenerative pump and compare the CFD results with new experimental data. The CFD results demonstrate that it is possible to represent the helical flowfield for the pump which has only been witnessed in experimental flow visualisation until now. The CFD performance results also demonstrate reasonable agreement with the experimental tests. The CFD models are currently being used to optimise key geometric features to increase pump efficiency.

Research into the installation and optimisation of turning vanes and drag reduction technology applied to the Landrover Discovery MK3 vehicle

Abstract: Details optimisation of front turning vanes and drag reduction for a Land Rover Discovery MK3.