Characteristic curves of centrifugal pumps are their head, kW (bhp), NPSHR and iso-efficiency curves plotted against capacity for a given rpm. They are extremely important in the pump selection process. Head/capacity curves come in several forms: a single curve that might represent the maximum ...
Experimental and numerical investigations have been carried out to study the behaviour of a centrifugal pump operating in direct mode or turbine mode. First of all, the complete characteristics (head, power, and efficiency) were measured experimentally u
Unstable or flat head-flow curves can cause problems in parallel operations or in flat systems. Despite the considerable efforts that have been devoted to the study of head-flow curve instability in single-stage centrifugal pumps with volute casing, the cause of such phenomenon is not sufficiently...
The procedure adopted in this paper is capable of obtaining performance characteristic curves of centrifugal pump in a dimensionless form. Pump head coefficient, manometric efficiency, power coefficient, and required NPSH are characterized. The predicted coefficients and obtained performance curves are ...
Performance curves of the centrifugal pump Full size image Figure5shows that under the operational conditions of volumetric flow rate ranging from 0.6Qspto 1.2Qsp, the relative errors of the numerical and test results on head and efficiency are within 2.98% and 2.88%, respectively. The numerical ...
The nature of variation of parameters during the transients has been discussed. The model-predicted dynamic head-capacity curves agree well with the experimental data for almost all the tested cases. 展开 关键词: NONLINEAR IDENTIFICATION MODEL VALIDATION ...
The load–displacement curves of large-diameter multi-disc soil anchors under five different conditions are obtained by Origin drawing software, as shown in Figs. 5 , 6, 7, 8, 9. Fig. 5 The load–displacement curve when n = 2. Full size image Fig. 6 The load–displacement curve...
In order to reduce amplitude of pressure fluctuation in a hydraulic turbine,a single-stage centrifugal pump was used as hydraulic turbine. A set of negative curvature guide vane was added next to the impeller outer diameter,then the performance of the turbine was studied experimentally. The geometr...
Cavitation characteristic curves Fig. 6 shows the curves of the head coefficientψand the vapor volume fractionαvin the impeller with the different cavitation number σ at the design flow rate. The formulas of cavitation number σ, head coefficientψand the vapor volume fractionαvare as follows...
Fig.7shows the four-quadrant performance curve obtained by the axial flow pump system experiment. Figure8shows a partially enlarged view of the energy characteristic curves of the axial flow pump system under three special utilization conditions. The flowQin Fig.8is dimensionlessly processed as follo...