The New Semi-Experimental Method for Simulation of Turbine Flow Meters Rotation in the Transitional Flow
The new semi-experimental method for simulation of the turbine flow meters rotation in the transitional flow has been developed. The method is based on the experimentally established exponential low of changing of dimensionless relative turbine gas meter rotation frequency and meter inertia time constant. For experimental evaluation of the meter time constant special facility has been developed. The facility ensures instant switching of turbine meter under test from one channel to the other channel with different flow rate and measuring the meter response. The developed method can be used for evaluation and predication of the turbine meters response and dynamic error in the transitional flow with any arbitrary law of flow rate changing. The examples of the method application are presented. Keywords—Dynamic error, pulsing flow, numerical simulation, response, turbine gas meters.
Turbine flowmeter response to transitional flow regimes
Abstract In this paper, acceleration and deceleration performance of turbine flowmeters was investigated in transitional flow regimes. Different flow meters and peak gas flow rates were used, with a step flow transition induced by rapid closing and reopening of the pipeline valve. Hotwire anemometry was employed as a reference method to assess the dynamic response of turbine flowmeters. Results of this study suggest a good dynamic response of turbine flowmeters in accelerating flows, with only a slight delay of the turbine rotation. However, in decelerating flows, the response of the flowmeter turbine was found to be slow, with characteristic time constants up to 35 s and large resulting over-registration of transferred gas volume. Our findings were quantified by multiple regression models for flowmeter response times and over-registered volumes, which were both find to drop with Reynolds number and increase with the flowmeter size. Understanding dynamic response is essential to evaluate dynamic errors and evaluate overall measurement uncertainty.
Constitutional Identity in the EU— A Shield or a Sword?
This Article consists of five sections. In the first section, it describes why identity questions matter, particularly in Europe. In the second section, the Article tackles the issue of multiple structural ambiguities affecting the concept of constitutional identity in the European constitutional vocabulary. In the third section, the Article explores trends concerning the use of constitutional identity in the European legal discourse and practice, including the development of alternative interpretations and applications of the notion of constitutional identities in the Member States. The fourth section of the Article combines the analytical accounts outlined in the second section with the trends identified in the third section, contending that different conceptions and applications of constitutional identity have varying effects on the European composite constitutional adjudication system and that the institutional and procedural framework should be calibrated accordingly. The final section of this Article draws some conclusions.