INVESTIGATION OF FLOW CONDITIONING IN PIPES |
|---|
| Gabriel Moniz Pereira, Bodo Mickan, Rainer Kramer, Dietrich Dopheide, Ernst von Lavante |
- Abstract:
- It is a well-known and recognised fact that the behaviour of flow rate and volume measuring devices can be affected very strongly by the flow conditions prevailing in their inlet pipe section. Disturbed velocity profiles caused by pipe configurations such as bends, headers, pressure regulators and convergent or divergent pipe sections in front of a flow meter can lead to deviations of the meter reading by up to several percents.
Thus, flow conditioning normally means the generation of fully developed flows in the inlet of meters to avoid installation effects. Since this is in practice not always possible, it is necessary to investigate the influence of flow perturbations to the behaviour of flow meters. Such investigations are normally part of pattern approval in legal metrology. Hence, in case of pattern approval flow conditioning means the generation of disturbed flows with a definite and reproducible level of perturbation. The International Organisation of Legal Metrology OIML defined therefore standard pipe configurations (e.g. in OIML Recommendation R 32) to perform perturbations test within pattern approvals.
The test configurations recommended by OIML were defined for applications in atmospheric air. The main reason for this narrowed view was the huge effort necessary to perform perturbation test under high pressure conditions. In praxis this leads to several problems, mainly if the meter under test (e.g. some ultra sonic meters) works only with high pressure gas or the meter behaviour have strong dependence on Reynolds number or pressure. In the first case the economic effort for pattern approval is very high and only a few test facilities are able to handle such configurations and in the second case it is a very sensitive question to transfer results from low pressure to high pressure conditions.
In this paper some results of investigation in the field of installation effects and flow conditioning done in PTB are shown concerning following points:
- differences of flow conditioning using real pipes under low and high pressure conditions,
- a new concept (perturbation plate) for generating definite disturbed flows which can easily performed under high pressure conditions and
- basic investigations to improve the application of CFD simulations to determine flow profiles from geometry of piping. - Download:
- IMEKO-TC9-2003-029.pdf
- DOI:
- -
- Event details
- IMEKO TC:
- TC9
- Event name:
- FLOMEKO 2003
- Title:
- 11th Conference on Flow Measurement
- Place:
- Groningen, NETHERLANDS
- Time:
- 12 May 2003 - 14 May 2003