Li-hua Piao, Tao Zhang, Tong Guo, Xiao-zhong Li, Xing Chen
Structural Optimization of Orifice Rotameter Based on CFD

The orifice rotameter indicates the flowrate as a displacement of a symmetrical body(float) placed concentrically downstream of an orifice inside a vertical tube. Experiments study had been performed at five positions of the float to evaluate the performance of the most commonly used type of orifice rotameter. The computational fluid dynamics (CFD) method was employed to optimize the performance of orifice rotameter. A total of 20 numerical models were established corresponding to the five positions, four types of orifice rotameter. At the same position, the floats of four types of numerical models have the same stroke with experimental flowmeter. Numerical models of 3D turbulence flow field of the orifice rotameter were conducted. The error analysis method of the float forced balance, which controls the computational precision, was adopted to adjust the inlet flowrate. The results of numerical calculation showed that new types of orifice rotameter improved the flow stability and linearity. The paper described the design and results to verify the performance of the new kinds of orifice rotameter.

Iryna Gryshanova
A Computational Investigation of Flow Meters

Computational fluid dynamics (CFD) techniques provide investigations in conditions where the real experiment can't be fulfilled for some reasons, so these tools have found their applications in many spheres of science and technology; in particular they are widely used in flow metering. Some of CFD applications we would like to propose and discuss in this work in the context of turbine and ultrasonic meters. We discover non-drag type of turbine flow meters to check if created design with hydro-dynamic bearings should provide really floating rotor. For this purpose only numerical research can solve verification problem with minimal costs and simple realisation. Another computational investigation is dedicated to transit-time ultrasonic flow meters to optimize their design and get improved performance not only in normal conditions.

Tao Wang, Yousif Hussain
Extending Flow Measurement Capacity with the Straighttube Coriolis Technology

Coriolis flowmeters had been mainly developed and used in line sizes less than DN100 (or 4-inch) because the size of the flow sensor itself could become too unwieldy and expensive for practical uses. This paper specifically reports the latest research and development of using the straight-tube Coriolis technology to extend flow measurement capacity to a high flow range. Design of the Coriolis flow sensor using a straight-tube configuration is firstly presented. Then, description of a special calibration procedure used in the manufacturer’s gravimetric water flow rig is provided. Finally, an extensive test programme within internal facilities and other independent facilities is also reported. Test results verified straight-tube flowmeters’ performance and showed a step forward in advancing the general Coriolis flowmetering technology.

Vivek Kumar, Martin Anklin, Benjamin Schwenter
Fluid-Structure Interaction (FSI) Simulations on the Sensitivity of Coriolis Flow Meter Under Low Reynolds Number Flows

In process industries Coriolis mass flow meters (CMFs) are widely employed for measuring mass flow rates. Quite often especially in oil and gas (O&G) industry, owing to fluids with high viscosities, flow measurements may lie in low Reynolds number regions. At low Reynolds numbers (Re), a CMF reading may deviate under the influence of fluid-dynamic forces. With the help of extensive Fluid-Structure- Interaction simulations (FSI), a detailed insight into physical mechanisms leading to this deviation is provided. The main finding is that this deviation is a function of the Reynolds number and the effect can be explained by a periodic shear mechanism which interacts with the oscillatory Coriolis force. Experimental results with and without the correction are shown and compared with corresponding numerical results.

Maria H. Farias, Marcos V. B. Ramos, Sandro R. Santoro
On the Dead Volume of a Standard Small Volume Prover

The calibration procedures of compact provers, which are used as standards to calibrate volumetric meters, are well known. However, the reduction of uncertainty of measurement in a prover calibration or when using a prover as standard depends on several factors, among them, the way of controlling some quantities, the kind of valves in the hydraulic circuit and how they are operated, the kind of liquid totalizer in calibration etc. In general, position sensors installed close to the initial and final ends of the cylinder ruler of the prover indicate the useful displacement along the tube. Such sensors limit the dead volume in the cylinder ends, which is not defined by the equipment user. On the other hand, if these dead regions, which are affected by the dynamics of the prover operation were evaluated by the user, the result could be different from that indicated by the supplier. The present work discusses that matter and, based on experimental data, analyzes the useful length for the cylinder of a small prover (09 L) which belongs to Inmetro (the Brazilian National Metrology Institute). A system for controlling and acquiring data has been created and adapted to the prover, and it is able to score pulses in two distinct counters, improving the equipment resolution. Besides making possible to investigate the size of dead spaces of the cylinder, such system could eliminated sensors at the final and initial positions of the tube ruler. The prover was calibrated by gravimetric water draw method under multiple samples along the cylinder length and using the two distinct pulses counters.