CFD Analysis and Improvement on an Insertion Electromagnetic Flowmeter

Author(s):  
Haibo Ma ◽  
Armin K. Silaen ◽  
Chenn Q. Zhou ◽  
Shilei Ma ◽  
Robert Moss ◽  
...  

Abstract Accurate measurement of the volumetric flow rate of working liquids is essential for process control, as well as energy consumption evaluation. Electromagnetic flowmeters have gained popularity in applications where low pressure drop and low maintenance are required. Dwyer Instruments, Inc., recently developed an adjustable insertion electromagnetic flowmeter (IEF) featuring accurate and reliable measurement. However, an unexpected and non-repeatable behavior in the K-factor was observed during the calibration process. The K-factor is the coefficient that is used to convert the measured electric potential to the flow velocity in pipes and the non-repeatable behavior imposes challenges for precise measurement. A one-way coupled magnetohydrodynamics model was developed to reduce the effort and time of on-site troubleshooting and optimization. By modeling the measurement process, the transition of flow regimes and the regeneration of boundary layer on the electrode surface were identified as the causes to the non-repeatable issue. Then, a series of parametric studies were performed to provide reliable solutions. A new design with further embedded electrodes was recommended. The field test showed great repeatability by using the new design and the non-repeatable issue was completely resolved. The improvement in the IEF design was implemented in production in less than one week and it reduced the calibration time by 50%.

Author(s):  
Haibo Ma ◽  
Shilei Ma ◽  
Robert Moss ◽  
Mark Fisher ◽  
Armin Silaen ◽  
...  

Abstract Accurate measurement of the volumetric flow rate of working liquids is essential for process control, as well as energy consumption evaluation. Electromagnetic flowmeters have gained popularity in applications where low-pressure drop and low maintenance are required. Dwyer Instruments, Inc. recently developed an adjustable insertion electromagnetic flowmeter (IEF) featuring accurate and reliable measurement. However, unexpected and non-repeatable behavior in the K-factor was observed during the calibration process. The K-factor is the coefficient used to convert the measured electric potential to the flow velocity in pipes, and the non-repeatable behavior imposes challenges for precise measurement. A one-way coupled magnetohydrodynamics model was developed to reduce the effort and time of on-site troubleshooting and optimization. By modeling the measurement process, the transition of flow regimes and the regeneration of the boundary layer on the electrode surface were identified as the causes of the non-repeatable issue. Then, a series of parametric studies were performed to provide reliable solutions. A new design with further embedded electrodes to allow the smooth transition between boundary layers was recommended. The field test showed excellent repeatability by using the new design, and the non-repeatable issue was entirely resolved. The improvement in the IEF design was implemented in production in less than one week, and it reduced the calibration time by 50%.


2016 ◽  
Vol 819 ◽  
pp. 356-360
Author(s):  
Mazharul Islam ◽  
Jiří Fürst ◽  
David Wood ◽  
Farid Nasir Ani

In order to evaluate the performance of airfoils with computational fluid dynamics (CFD) tools, modelling of transitional region in the boundary layer is very critical. Currently, there are several classes of transition-based turbulence model which are based on different methods. Among these, the k-kL- ω, which is a three equation turbulence model, is one of the prominent ones which is based on the concept of laminar kinetic energy. This model is phenomenological and has several advantageous features. Over the years, different researchers have attempted to modify the original version which was proposed by Walter and Cokljat in 2008 to enrich the modelling capability. In this article, a modified form of k-kL-ω transitional turbulence model has been used with the help of OpenFOAM for an investigative CFD analysis of a NACA 4-digit airfoil at range of angles of attack.


Author(s):  
Tom I-P. Shih ◽  
Yu-Liang Lin ◽  
Andrew J. Flores ◽  
Mark A. Stephens ◽  
Mark J. Rimlinger ◽  
...  

Abstract A pre-processor was developed to assist CFD experts and non-experts in performing steady, three-dimensional Navier-Stokes analysis of a class of inlet-bleed problems involving oblique shock-wave/ boundary-layer interactions on a flat plate with bleed into a plenum through rows of circular holes. With this pre-processor, once geometry (e.g., hole dimensions and arrangement) and flow conditions (e.g., Mach number, boundary-layer thickness, incident shock location) are inputted, it will automatically generate every file needed to perform a CFD analysis from the grid system to initial and boundary conditions. This is accomplished by accessing a knowledge base established by experts who understand both CFD and the class of problems being analyzed. For experts in CFD, this tool greatly reduces the amount of time and effort needed to setup a problem for CFD analysis. It also provides experts with knobs to make changes to the setup if desired. For non-experts in CFD, this tool enables reliable and correct usage of CFD. A typical session on a workstation from data input to the generation of all files needed to perform a CFD analysis involves less than ten minutes. This pre-processor, referred to as AUTOMAT-V2, is an improved version of a code called AUTOMAT. Improvements made include: (1) multi-block structured grids can be patched in addition to being overlapped; (2) embedded grids can be introduced near bleed holes to reduce the number of grid points/cells needed by a factor of up to four; (3) grid systems generated allow up to three levels of multigrid; (4) CFL3D is supported in addition to OVERFLOW, two well-known and highly regarded Navier-Stokes solvers developed at NASA’s Langley and Ames Research Centers; (5) all files needed to run RONNIE for patched grids and MAGGIE for overlapped grids are also generated; and (6) more design parameters can be investigated including the study of micro bleed and effects of flow/hole misalignments.


2011 ◽  
Vol 135-136 ◽  
pp. 852-855
Author(s):  
Yin Ping Jiang ◽  
Shan Liu ◽  
Yun Hua Yang

At present, the energy crisis is increasingly serious. Energy-saving becomes a practical issues faced by all fields in the life. Considering this, the paper presents a new vehicle consumption measuring system based on intelligent handling and humane design under the promise of accurate measurement as well as low cost. In addition, the use of radio frequency communication technology makes precise measurement of instant and accumulative fuel consumption come true in any working hours. Field experiment results show that the vehicle fuel consumption measuring system has character of facilitate operation, low cost, advanced and reliable measurement method and high accuracy (within 1.5%). It can improve greatly the production efficiency of the internal combustion machine and avoid effectively the waste phenomenon, and be prone to make further application widely.


2009 ◽  
Vol 626-627 ◽  
pp. 159-164 ◽  
Author(s):  
Chang He Li ◽  
Ya Li Hou ◽  
Yu Cheng Ding ◽  
Bing Heng Lu

In the grinding process, grinding fluid is delivered for the purposes of chip flushing, cooling, lubrication and chemical protection of work surface. Due to high speed rotating grinding wheel, the boundary layer of air around the grinding wheel restricts most of the grinding fluid away from the grinding zone. Hence, conventional method of delivering grinding fluid that flood delivery is not believed to fully penetrate this boundary layer and, thus, the majority of the grinding fluid is deflected away from the grinding zone. The flood grinding typically delivers large volumes of grinding fluid was ineffective, especially under high speed grinding conditions. In the paper, a theoretical model is presented for flow of grinding fluid through the grinding zone. The model shows that the flow rate through the contact zone between the wheel and the work surface depends on wheel porosity and wheel speed as well as depends on nozzle volumetric flow rate and fluid jet velocity. Furthermore, the model was tested by a surface grinding machine in order to correlate between experiment and theory. Consequently, the effective flow-rate model was found to give a good description of the experimental results and the model can well forecast the effective flow-rate in flood delivery grinding.


Author(s):  
S N Singh ◽  
L Rai ◽  
P Puri ◽  
A Bhatnagar

The effect on aerodynamic drag using a model of a truck has been investigated by controlling the boundary layer separation by the momentum injection method using a rotating cylinder. It involves the use of experiments coupled with computational fluid dynamics (CFD) analysis to validate the theory of momentum injection. Modelling of the truck has been done on the software GAMBIT©. The best suitable turbulence model was selected by comparing the results with the experimental results. The rotational speed and radius of the cylinder are varied to establish the effect of momentum injection on aerodynamic drag. The coefficient of drag reduces by approximately 35 per cent from an initial value of 0.51-0.32 for a cylinder of radius 1 cm with rotational speed of 4000 r/min.


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