Showing papers by "Matthew Stickland published in 2000"

Numerical flow simulation in a centrifugal pump with impeller - volute interaction

Abstract: This paper shows a numerical simulation of the tree-dimensional fluid flow inside a centrifugal pump. The pump is a commercial centrifugal water pump with a 190 mm outlet impeller diameter, backward curved blades, nominal flow of 0.013 m3/s and 11 m of head. This simulation has been made with an unsteady calculation and using the sliding mesh technique to take into account the impeller-volute interaction. With them, it is possible to simulate correctly the blade passage in front of the tongue and the flow and pressure fluctuations induced. The numerical results are compared with the experimental characteristic curve and pressure fluctuations measured in the volute. The data obtained allow the analysis of the main phenomena existent in these pumps, such as: the pressure changes in the volute for different flow rates; the incidence at the leading edge of the blade with different flow conditions; and the secondary flow generated in the volute due to the width change between the impeller and the volute.

Numerical simulation of centrifugal pumps

Abstract: The power computers increase and the specific calculation software development have made possible, nowadays, the numerical simulation of flow and energy transfer inside the turbomachinery. To teach Fluid Mechanics is not easy not only for the professors but also for the students because the theoretical part must be complemented with a technical part where students can see the phenomena. However, specially in hydraulic turbomachinery, we canit see the phenomena except if we have a specific material, for example a PIV. Even if we would have this material, the access to specific parts of turbomachinery is not possible due to its constructive layout. The use of numerical simulation tools allows us to obtain data in inaccessible positions for the experimentation, as well as the study of unusual or dangerous performances. With the numerical simulation, the pressure fluctuation at any point of the pump can be easily obtained. Other important results are the radial forces on the impeller, which have a significant variation with the working points. One of the advantages of this kind of modelling is the ease to carry out changes in the geometry, parametric studies and analysis of anomalous operation conditions.

An experimental study on the unsteady pressure distribution around the impeller outlet of a centrifugal pump

Abstract: An experimental investigation is presented which analyzes the fluctuating pressure field existing in the volute of a centrifugal pump, in order to characterize the effects of blade-tongue interaction. For that purpose, pressure signals were obtained simultaneously at different locations on the volute casing and for different flow-rates by means of fast-response pressure transducers. Particular attention was paid to the pressure fluctuations at the blade passage frequency, regarding both amplitude and phase delay relative to the motion of the blades. The dependence of the obtained pressure fluctuations with respect to both flow-rate and position along the volute clearly indicates the leading role played by the tongue in the impeller-volute interaction and the strong increase of the magnitude of the dynamic forces in off-design conditions.

Introducing instrumentation and data acquisition to mechanical engineering students using LabVIEW

Abstract: For several years, LabVIEW has been used within the Department of Mechanical Engineering at the University of Strathclyde as the basis for introducing the basic concepts and practice of data acquisition, and more generally, instrumentation, to postgraduate engineering students and undergraduate project students. The objectives of introducing LabVIEW within the curriculum were to expose students to instrumentation and experimental analysis, and to create courseware that could be used flexibly for a range of students. It was also important that staff time for laboratory work be kept to manageable levels. A course module was developed which allows engineering students with very little or no previous knowledge of instrumentation or programming to become acquainted with the basics of programming, experimentation and data acquisition. The basic course structure has been used to teach both undergraduates and postgraduates as well as laboratory technical staff. The paper describes the objectives of the use of LabVIEW for teaching, the structure of the module developed, and the response of students who have been subjected to the course, and how it is intended to expand the delivery to greater student numbers.

Ironwork of Teixois-Taramundi (Asturias), Spain

Abstract: This paper describes and old ironwork placed in a Spanish village. All parts of it are studied, specially the Air supply and the Hydraulic wheel. The minimum area in the water trump for a correct air flow is calculated. On the other hand, also the power supply by the hydraulic wheel, in normal conditions, to move the hammer with a required frequency is calculated.