Linking Efficiency to Functional Performance by a Pump Test Standard for Wastewater Pumps

2015 ◽  
Author(s):  
Michael Pöhler ◽  
Stefan Gerlach ◽  
Kristian Höchel ◽  
Tino Mengdehl ◽  
Paul Uwe Thamsen
Keyword(s):  
Functional Performance ◽  
Complex Flow ◽  
Pump Operation ◽  
Pump Test ◽  
Wastewater Systems ◽  
Transport Behaviour ◽  
Institute Of Technology ◽  
Complex Flow Structure ◽  
Multi Phase ◽  
Phase Fluid

Upcoming Energy related Products (ErP) regulations on wastewater pumps by the European Commission will affect all pump manufacturers and operators of wastewater systems. Hence, the preparation of efficiency standards for wastewater pumps is intensively accompanied by input from the affected stakeholders and experts of different fields [1]. The previous approaches of ErP regulations, as in lot 11 (Electric motors, Ventilation fans, Circulators in buildings, Electric pumps), focus only on efficiency. However, when applying the philosophy of Ecodesign directly to wastewater pumps, the complex flow structure and the transport behaviour of this inhomogeneous multi-phase fluid must be taken into account. While efficiency is an important criterion, it is necessary to take the specifics of sewage transport into account when designing a new test standard, so as not to compromise on proven and “system-efficient” technologies. Therefore, the Berlin Institute of Technology is currently investigating wastewater compositions and limits for reliable pump operation in order to design a test standard for wastewater pumps comparable to the DIN EN ISO 9906 efficiency tests for clear water [2]. The test will assess the functional fulfilment level of the pump performance, differentiating between the wastewater classes.

scholarly journals Low-cost Solutions for Velocimetry in Rotating and Opaque Fluid Experiments using Ultrasonic Time of Flight

2021 ◽  
Author(s):  
Fabian Burmann ◽  
Jerome Noir ◽  
Stefan Beetschen ◽  
Andrew Jackson
Keyword(s):  
Acoustic Waves ◽  
Flow Measurement ◽  
Low Cost ◽  
Time Of Flight ◽  
Zonal Flow ◽  
Gravitational Acceleration ◽  
Complex Flow ◽  
Ultrasonic Time ◽  
Theoretical Predictions ◽  
Complex Flow Structure

AbstractMany common techniques for flow measurement, such as Particle Image Velocimetry (PIV) or Ultrasonic Doppler Velocimetry (UDV), rely on the presence of reflectors in the fluid. These methods fail to operate when e.g centrifugal or gravitational acceleration leads to a rarefaction of scatterers in the fluid, as for instance in rapidly rotating experiments. In this article we present two low-cost implementations for flow measurement based on the transit time (or Time of Flight) of acoustic waves, that do not require the presence of scatterers in the fluid. We compare our two implementations against UDV in a well controlled experiment with a simple oscillating flow and show we can achieve measurements in the sub-centimeter per second velocity range with an accuracy of $\sim 5-10\%$ ∼ 5 − 10 % . We also perform measurements in a rotating experiment with a complex flow structure from which we extract the mean zonal flow, which is in good agreement with theoretical predictions.

Fluid Flow Structure in Arterial Bypass Anastomosis

2005 ◽  
Vol 127 (4) ◽  
pp. 611-618 ◽  
Author(s):  
C. M. Su ◽  
D. Lee ◽  
R. Tran-Son-Tay ◽  
W. Shyy
Keyword(s):  
Fluid Flow ◽  
Flow Structure ◽  
Bypass Graft ◽  
Flow Characteristics ◽  
Navier Stokes ◽  
Complex Flow ◽  
Arterial Bypass ◽  
Flow Recirculation ◽  
Area Reduction ◽  
Complex Flow Structure

The fluid flow through a stenosed artery and its bypass graft in an anastomosis can substantially influence the outcome of bypass surgery. To help improve our understanding of this and related issues, the steady Navier-Stokes flows are computed in an idealized arterial bypass system with partially occluded host artery. Both the residual flow issued from the stenosis—which is potentially important at an earlier stage after grafting—and the complex flow structure induced by the bypass graft are investigated. Seven geometric models, including symmetric and asymmetric stenoses in the host artery, and two major aspects of the bypass system, namely, the effects of area reduction and stenosis asymmetry, are considered. By analyzing the flow characteristics in these configurations, it is found that (1) substantial area reduction leads to flow recirculation in both upstream and downstream of the stenosis and in the host artery near the toe, while diminishes the recirculation zone in the bypass graft near the bifurcation junction, (2) the asymmetry and position of the stenosis can affect the location and size of these recirculation zones, and (3) the curvature of the bypass graft can modify the fluid flow structure in the entire bypass system.

Natural Convection in a Horizontal Cavity Partially Occupied by a Porous Media Saturated by a Coolant Liquid

2006 ◽  
Author(s):  
Fakhreddine S. Oueslati ◽  
Rachid Bennacer ◽  
Habib Sammouda ◽  
Ali Belghith
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Natural Convection ◽  
Flow Structure ◽  
Boussinesq Approximation ◽  
Density Variation ◽  
Heat Fluxes ◽  
Complex Flow ◽  
Coupled Equations ◽  
Complex Flow Structure

The natural convection is studied in a cavity witch the lower half is filled with a porous media that is saturated with a first fluid (liquid), and the upper is filled with a second fluid (gas). The horizontal borders are heated and cooled by uniform heat fluxes and vertical ones are adiabatic. The formulation of the problem is based on the Darcy-Brinkman model. The density variation is taken into account by the Boussinesq approximation. The system of the coupled equations is resolved by the classic finite volume method. The numerical results show that the variation of the conductivity of the porous media influences strongly the flow structure and the heat transfer as well as in upper that in the lower zones. The effect of conductivity is conditioned by the porosity which plays a very significant roll on the heat transfer. The structures of this flow show that this kind of problem with specific boundary conditions generates a complex flow structure of several contra-rotating two to two cells, in the upper half of the cavity.

scholarly journals Experimental study of weak shock waves influence on the supersonic boundary layer of the flat plate model

2019 ◽  
Vol 196 ◽  
pp. 00018 ◽  
Author(s):  
Vasiliy Kocharin ◽  
Aleksandr Kosinov ◽  
Yuriy Yermolayev ◽  
Nikolay Semionov
Keyword(s):  
Boundary Layer ◽  
Experimental Study ◽  
Shock Waves ◽  
Flat Plate ◽  
Leading Edge ◽  
Weak Shock ◽  
Supersonic Boundary Layer ◽  
Complex Flow ◽  
Complex Flow Structure ◽  
Constant Temperature Anemometer

The experimental study of the effect of weak shock waves on the supersonic boundary layer of the flat plate with a blunt leading edge (the radius of bluntness was r = 2.5 mm) with Mach number M = 2.5 and zero angle of attack was carried out. The measurements were carried out using the constant temperature anemometer. The paper presents a complex flow structure on the surface of the model. High-intensity peaks were found in the regions of the disturbed flow. Also the spectral analysis of perturbations was performed. It is found that the supersonic boundary layer on a flat plate is very sensitive to the effect of weak shock waves.

Flow Field Analysis of Under-Expanded Supersonic Jets Impinging on an Inclined Flat Plate: Analysis With PSP/Schlieren Images and CFD Simulations

2005 ◽  
Author(s):  
Kozo Fujii ◽  
Akira Oyama ◽  
Nobuyuki Tsuboi ◽  
Moto Tsukada ◽  
Hirofumi Ouchi ◽  
...  
Keyword(s):  
Flat Plate ◽  
Flow Structure ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Flow Fields ◽  
Field Analysis ◽  
Geometrical Parameters ◽  
Complex Flow ◽  
Plate Analysis ◽  
Complex Flow Structure

Flow fields of Mach number 2.2 jet impinging on an inclined flat plate are experimentally investigated using the Pressure Sensitive Paints (PSP) and Schlieren flow visualization. The flow filed structure is mainly determined by two geometrical parameters (nozzle-plate distance and plate angle against the jet) and one flow parameter (pressure ratio). The results suggest that all the observed flow fields can actually be classified into three types of flow structure based on the three parameters above. As an extension of the authors’ earlier work, experiments are carried out for higher plate angles. The new results show the effectiveness and limitation of the classification that we proposed. To find out the flow structure, some of the flow fields are computationally simulated. Good agreement of the pressure distributions with the experiment validates the simulation. Although analysis so far is limited, the result reveals three dimensional complex flow structure that created pressure peaks over the plate surface.

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