Traceability Flow Research Articles

Measurement corrections for temperature effects in Coriolis mass flow meters for cryogenic, liquid hydrogen (LH2) applications

To link traceable flow calibrations of Coriolis meters at ambient conditions to flow measurements in cryogenic, liquid hydrogen (LH2) applications, physical effects of very low temperatures on the calibration factor must be satisfactorily predicted by temperature correction methods. In this paper, four correction models are investigated, which differ in the sense of which temperature effects they cover and how these effects are determined. These correction models were applied to three Coriolis meter designs – straight, arc and U-tube. As a reference value in the evaluation, we use the simulation results with the finite element model that incorporates temperature effects related to elastic material properties, thermal strains and thermal stresses. The best agreement (within ± 0.2 % for the curved tubes) is achieved by the correction model that considers the known temperature dependence of the tube elastic properties as well as the dimensional changes due to thermal strain.

Study on the provision of traceable flow rate of water vapor for calibrating a time-of-flight mass spectrometer

Forming a traceable flow rate is the key to mass spectrometer calibration, and the flow rate can be calculated through the conductance. The theoretical and experimental analysis of measuring the conductance of water vapor using the VΔp measurement method is presented, the measurement error of that method increases with the decrease of flow rate, which is due to the strong adsorption characteristic of water vapor. Based on the VΔp measurement method, a new method called the pΔt measurement method is proposed to give the relationship between the orifice conductance and the inlet pressure for water vapor, and the conductance can be calculated by measuring the time of pressure change, which can correct the adsorption influence of water vapor on the measurement of conductance. The relative standard uncertainty of the pΔt measurement method is 8%. The conductance of an orifice, whose diameter is about 22.2 µm, was measured by that method, and the measurement results agree well with the theoretical values. According to those two methods, an apparatus was developed to calibrate a miniature time-of-flight mass spectrometer (TOF-MS) for water vapor, and it can supply the flow rate of water vapor in the range from 3.67 × 10−9 to 2.19 × 10−5 Pa m3 s−1. Finally, there is a linear relationship between the signal and the flow rate for water vapor in the range from 1.39 × 10−8 to 1.29 × 10−5 Pa m3 s−1.

Fast Coherent Video Style Transfer via Flow Errors Reduction

For video style transfer, naively applying still image techniques to process a video frame-by-frame independently often causes flickering artefacts. Some works adopt optical flow into the design of temporal constraint loss to secure temporal consistency. However, these works still suffer from incoherence (including ghosting artefacts) where large motions or occlusions occur, as optical flow fails to detect the boundaries of objects accurately. To address this problem, we propose a novel framework which consists of the following two stages: (1) creating new initialization images from proposed mask techniques, which are able to significantly reduce the flow errors; (2) process these initialized images iteratively with proposed losses to obtain stylized videos which are free of artefacts, which also increases the speed from over 3 min per frame to less than 2 s per frame for the gradient-based optimization methods. To be specific, we propose a multi-scale mask fusion scheme to reduce untraceable flow errors, and obtain an incremental mask to reduce ghosting artefacts. In addition, a multi-frame mask fusion scheme is designed to reduce traceable flow errors. In our proposed losses, the Sharpness Losses are used to deal with the potential image blurriness artefacts over long-range frames, and the Coherent Losses are performed to restrict the temporal consistency at both the multi-frame RGB level and Feature level. Overall, our approach produces stable video stylization outputs even in large motion or occlusion scenarios. The experiments demonstrate that the proposed method outperforms the state-of-the-art video style transfer methods qualitatively and quantitatively on the MPI Sintel dataset.

Flow measurement challenges for carbon capture, utilisation and storage

Carbon Capture, Utilisation and Storage (CCUS) is a key element in the United Kingdom Government strategy for reducing carbon dioxide (CO2) emissions. The UK aims to capture and store 10 million tonnes of CO2 each year by 2030.At each stage in the CCUS infrastructure, accurate measurement of the CO2 flow rate is required, over a range of temperatures, pressures, flow rates and fluid phases, where the flow measurement must be validated through a credible traceability chain. The traceability chain provides the underpinning confidence required to verify meter performance, financial and fiscal transactions, and environmental compliance. The UK equivalent of the EU Emissions Trading System (EU ETS) specifies a maximum uncertainty value for CO2 flow measurement. Accordingly, the provision of accurate and traceable flow measurement of CO2 is a prerequisite for an operational CCUS scheme.However, there are currently no CO2 flow measurement facilities, nationally or internationally, providing traceable flow calibrations of gas phase, liquid/dense phase and supercritical phase CO2 that replicate real-world CCUS conditions. This lack of traceable CO2 gas and liquid flow measurement facilities and associated flow measurement standards is a significant barrier to the successful implementation of CCUS projects worldwide.This paper presents an overview of the traceability chain required for CO2 flow measurement in the UK and globally. Current challenges are described along with potential solutions and opportunities for the flow measurement community.

Tecnología blockchain en la optimización de una cadena de suministro

La presente investigación, tiene como objetivo proponer un modelo de cadena de suministro que sea soportado por la tecnología blockchain a través del desarrollo de contratos inteligentes. Se establecen especificaciones funcionales que cumplan con la propuesta a través de la selección de herramientas tecnológicas, para la construcción de un contrato inteligente, en donde se especifica su distribución como: estructuras, variables de estado y funciones, que brindan solución a los requerimientos del modelo en base a un ejemplo realizado en el sector farmacéutico. Simulando la interacción dentro de una red Ethereum de prueba con la finalidad de analizar el flujo de trazabilidad de un producto, a través de la intervención de participantes dentro de la cadena de suministro como pueden ser: fabricantes, proveedores o clientes.

Hybrid simulation of a segmental orifice plate

Computational fluid dynamics (CFD) has become a popular tool in the development of flow meters as an alternative to cost-intensive prototyping while preparing for approval tests or particular disturbances in pipe systems. In practical CFD applications, a turbulence model is required to predict the influence of turbulent flow features. Unfortunately, even the most state-of-the-art and commonly used turbulence models – the Reynolds-averaged Navier-Stokes (RANS) models – perform rather poorly in complex and separated flows, while scale-resolving methods such as large eddy simulations (LES) remain unfeasible for most industrial applications and higher Reynolds numbers. To make use of LES accuracy and current computing capacities nonetheless, the utilization of hybrid RANS-LES methods represents an efficient solution today.In this paper, we present a modified stress-blended eddy simulation (SBES) turbulence model capable of making reliable predictions of disturbed pipe flows and the resulting effects on flow meter measurements demonstrated by simulating a segmental orifice plate and its influence on an ultrasonic meter. To illustrate the differences, the SBES results are compared to those of a standard k-ω RANS model. Typical mesh requirements and solver settings are discussed. Also, a spatially dependent blending function for SBES is introduced. Both simulations are compared to a large number of laser Doppler anemometry (LDA) and ultrasonic clamp-on measurements performed on a gravimetrically traceable flow test facility. The comparison with LDA shows the clear superiority of SBES, where RANS fails due to a massive overestimation of the recirculation zone. Near the orifice, SBES even has an advantage over LDA in predicting the ultrasonic meter performance.

Primary standard for liquid flow rates between 30 and 1500 nl/min based on volume expansion.

An increasing number of microfluidic systems operate at flow rates below 1 μl/min. Applications include (implanted) micropumps for drug delivery, liquid chromatography, and microreactors. For the applications where the absolute accuracy is important, a proper calibration is required. However, with standard calibration facilities, flow rate calibrations below ~1 μl/min are not feasible because of a too large calibration uncertainty. In the current research, a traceable flow rate using a certain temperature increase rate is proposed. When the fluid properties, starting mass, and temperature increase rate are known, this principle yields a direct link to SI units, which makes it a primary standard. In this article, it will be shown that this principle enables flow rate uncertainties in the order of 2-3% for flow rates from 30 to 1500 nl/min.

Reynolds number dependence of an orifice plate

One of the most important process parameters in power plants is the flow rate that is measured in the secondary or feedwater circuit. To improve our understanding of the behaviour of flow instruments for this use, a work package within the European research project JRP “Metrology for improved power plant efficiency” concerning “Flow” was initiated. It comes under the direction of SP, Technical Research Institute of Sweden. Many power plants have to operate below their licensed rating because of the measurement uncertainty of the flow in the feedwater circuit. For that reason – in the field of traceable flow measurement – four European NMIs (PTB, SP, DTI, BEV) investigated four flow sensors based on different measuring principles. The aim is to find a method to extrapolate low temperature calibrations to high temperatures in order to measure feedwater flow with an uncertainty in the range of 0.3%–0.5%. This paper describes the work undertaken at SP on investigations of an orifice plate.