Determination of the prototype performance from model acceptance tests of hydraulic machines with the consideration of scale effects

1995 ◽  
Keyword(s):  
Scale Effects ◽  
Hydraulic Machines ◽  
Acceptance Tests

Transferring Methods of Efficiency for Hydraulic Machines Using Model Based on Smooth-Pipes Flow

2008 ◽  
Author(s):  
Li Long ◽  
Ze Wang ◽  
Xuelin Yang ◽  
Dan Li
Keyword(s):  
Reynolds Number ◽  
Scale Effects ◽  
Head Loss ◽  
Computational Method ◽  
Prototype Model ◽  
Hydraulic Efficiency ◽  
Number Range ◽  
Model Based ◽  
Hydraulic Machines ◽  
Acceptance Tests

The scope of Reynolds number in the model experiment and the serviceability on Blasius friction factor equation were analyzed. The exponent of prototype–model scale and the proper distribution of the friction and vortex head loss in Moody’s formula were studied. It was consider that the friction head loss could not be reduced with the accession of vortex head loss. New conversion method of hydraulic efficiency for prototype pump performance using model based on Prandtl-Colebrook formula with a wide Reynolds number range and Nikuradse’s experiments to be consistent with was proposed The conversion results was compared with IEC 60995:1991, JIS B 8327:2002 methods. It is indicated that Prandtl-Colebrook formula has advantage of the strongly theoretical elements, the simply computational method and the high computation precision. It can be becoming to confirm of the prototype hydraulic efficiency from model acceptance tests of hydraulic machines with consideration of scale effects.

scholarly journals Evaluation of capabilities of the nanoindentation test in the determination of flow stress characteristics of the matrix material in porous sinters

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Lukasz Madej ◽  
Adam Legwand ◽  
Mohan Setty ◽  
Mateusz Mojzeszko ◽  
Konrad Perzyński ◽  
...  
Keyword(s):  
Flow Stress ◽  
Scale Effects ◽  
Imaging Techniques ◽  
Matrix Material ◽  
Indentation Load ◽  
Nanoindentation Test ◽  
Load Range ◽  
Nanoindentation Measurement ◽  
The Matrix

AbstractHerein, we evaluate the nanoindentation test capabilities in the determination of flow stress characteristics of the matrix material in porous sinters. The Distaloy AB sample with 15% porosity after the sintering operation is selected as a case study for the investigation. 2D and 3D imaging techniques are employed first to highlight difficulties in identifying reliable nano hardness measurement zones for further properties evaluation. Then, nanoindentation test results are acquired with Berkovich tip pressed under various loads at different locations in the sample. Systematic indentations in the quartz sample are used as a cleaning procedure to minimize the effect of the possible build-up around the indenter tip. The representative indentation load range is selected based on the extracted material characteristics. With that, the stress–strain response of the sinter matrix material is identified. The reliability of the determined flow stress curve is confirmed with the use of conical nanoindentation measurement results and finite element simulations. Obtained results show that it is possible to calculate reliable flow stress characteristics of the matrix in the porous samples, with the assumption that experiments under various loading conditions and from various locations in the matrix are performed. It is also pointed out that various indentation loads should be used to eliminate the influence of the pile-up or scale effects that affect the overall material response.

scholarly journals Atmospheric CO2, CH4, and CO with CRDS technique at the Izaña Global GAW station: instrumental tests, developments and first measurement results

2017 ◽  
Author(s):  
Angel J. Gomez-Pelaez ◽  
Ramon Ramos ◽  
Emilio Cuevas ◽  
Vanessa Gomez-Trueba ◽  
Enrique Reyes
Keyword(s):  
Drift Rate ◽  
Inlet Pressure ◽  
Response Functions ◽  
Measurement Results ◽  
Ambient Measurements ◽  
Acceptance Tests ◽  
Term Maintenance

Abstract. At the end of 2015, a CO2/CH4/CO Cavity Ring-Down Spectrometer (CRDS) was installed at the Izaña Global Atmosphere Watch station (Tenerife, Spain) to improve the Izaña Greenhouse gases GAW measurement programme, and to guarantee the renewal of the instrumentation and the long-term maintenance of this programme. We present the results of the CRDS acceptance tests, the processing of raw data applied through novel numerical codes, and the response functions used. Also, the calibration results, the implemented water vapour correction, the target gas injection statistics, the ambient measurements performed from December 2015 to July 2017, and their comparison with other continuous in situ measurements are described. The agreement with other in situ continuous measurements is good most of the time for CO2 and CH4, but for CO is just outside the GAW 2-ppb objective. It seems the disagreement is not produced by significant drifts in the CRDS CO WMO tertiary standards. The main novelties are: 1) determination of a slight CO2 correction that takes into account changes in the inlet pressure/flow rate; 2) detailed justification of the use of virtual tanks to monitor the response function changes in time; 3) drift rate determination for the pressure and temperature sensors located inside the CRDS cavity; 4) novelties in the determination of the H2O correction for CO; and 5) determination and discussion of the origin of the CRDS-flow inlet pressure and H2O dependences.

Centerwell Water Motions and Hydrodynamic Loading Using Viscous Flow Calculations

2008 ◽  
Author(s):  
Samuel Holmes ◽  
Joseph Gebara ◽  
Allan Magee
Keyword(s):  
Scale Effects ◽  
Vertical Motion ◽  
Scale Model ◽  
Navier Stokes ◽  
Open Area ◽  
Flow Models ◽  
Free Surface Waves ◽  
Natural Response ◽  
Termination Point

Most Spar platforms have a wet centerwell which provides a termination point for umbilicals and risers. The column of water in the centerwell is a dynamic system which can be excited by the wave action around the Spar as well as the platform’s own motions. When the exciting frequencies are close to the natural frequency of the water column, the vertical motion of the water in the centerwell can become large in large seastates. This might damage structures within the centerwell. A natural response to this problem is to restrict the fluid flow at the bottom of the centerwell by adding a plated structure to partially close the opening. The remaining open area in the centerwell determines the amount of damping as well as the loads on the plating which can be quite large in heavy seas. The problem addressed in this paper is the determination of the appropriate open area in the centerwell plate that will control the fluid vertical motion without requiring expensive reinforcements to the plating beyond the riser guide structure already present. Traditional design tools based on potential flow models appear to perform poorly for this problem because they do not model the viscous damping in the flow correctly. In this paper we use a Navier-Stokes solver to study the centerwell motions and centerwell plate loads for three centerwell plate geometries. It is found that the Spar motions and the free surface waves need to be included in these simulations. The centerwell water motions and centerwell plate loads are compared with those measured in a scale model experiment. Full-scale calculations are also carried out to determine the corresponding centerwell plate loads and centerwell water motions to assess scale effects.

scholarly journals SCALE EFFECT IN LABORATORY DETERMINATION OF THE PROPERTIES OF COMPLEX CARBONATE RESERVOIRS

2020 ◽  
Author(s):  
Kamensky IP ◽  
Sudad H Al-Obaidi ◽  
Khalaf FH
Keyword(s):  
Scale Effect ◽  
Large Scale ◽  
Scale Effects ◽  
Rock Properties ◽  
Flow Capacity ◽  
Core Study ◽  
Porosity And Permeability ◽  
Relationship Of ◽  
The Relationship

As it is well known that, formation porosity and permeability are fundamental rock properties. Porosity is a measure of the storage capacity of the rock and permeability is a measure of rock flow capacity. In this study the relationship of the scale effect with the features and type of the capacitive structure of complex reservoirs is shown. The characteristic conditions for the manifestation of large-scale effects in determining porosity and permeability are analyzed. Also in this work the influence of the scale effect on the representativeness of laboratory determinations of flow- storage capacitance (FSC) properties is shown. The relationship between the values of porosity and permeability with the object of the core study has been established.

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