A comparative study of flow rate characteristics of an averaging Pitot tube type flow meter according to H parameters based on two kinds of differential pressure measured at the flow meter with varying air temperature

Dae-San Oh1, Choong-Hoon Lee1
1Department of Automotive Engineering, Seoul National University of Science and Technology, Seoul, Korea

Tóm tắt

A new averaging Pitot tube flow meter that has a shape similar to an Annubar® type flow meter was designed and its flow rate characteristic was evaluated. The air temperature supplied to the developed flow meter was maintained at a constant by controlling electric power supply to an electric heater during the calibration. Two kinds of differential pressure measured at the flow meter were used in calculating the H parameters, which represent characteristics of the developed flow meter. One H parameter (HΔP1) which was newly proposed in this research was calculated based on the difference between upstream pressure (stagnation pressure) at the flow meter and static pressure of the measured flow. The differential pressure is equivalent to the dynamic pressure of the flow. The other H parameter (HΔP2) which is used in a typical Annubar® type flow meter was calculated based on the difference between upstream and downstream pressure at the developed flow meters. Relationship curves between the two H parameters and the mass flow rate at the developed flow meter were obtained. The curves based on the HΔP2 parameter, which uses the difference between up and down stream pressure, show different gradients for varying the controlled air temperature. However, the other curve, based on the other HΔP1 parameter, which uses the dynamic pressure, can be represented by one linear curve even with varying air temperature.

Từ khóa


Tài liệu tham khảo

H. S. Bean, Fluid meters their theory and application, ASME, Sixth Edition, USA (1971).

ISA 1932 (ISO-5167-3), Measurement of fluid flow by means of pressure differential devices inserted in circular-cross section conduits running full-part3:nozzle and venturi nozzle, International Organization for Standardization (2003).

S. Tavoularis, Measurement in fluid mechanics, Cambridge University Press, New York, USA (2005).

R. C. Baker, Flow measurement handbook, Cambridge University Press, New York, USA (2000).

Rosemount product data sheet, Diamond II-Annubar® bar primary flow element, dieterich, a subsidiary of Rosemount Inc. (1998).

E. M. Shanahan, J. E. Garnett, R. J. Gray and G. Dragnea, Method for calibrating a differential pressure fluid flow measuring system, US Patent 5710370 (1998).

C. Britton and D. A. Mesnard, Performance survey round and diamond-shaped averaging Pitot type primaries, Meas. Control, 15 (1982) 341–350.

G. D. Cutler, Averaging pitot-type primaries, Meas. Control, 15 (1982) 436–437.

C. H. Lee, Effects of pressure tapping conditions on flow rate measurement of triangular separate bar differential pressure flow meter, Journal of Korean Society of Safety, 25(2) (2010) 1–6.

H. Nakamura, N. Kihara, M. Adachi and K. Ishida, Development of a wet-based NDIR and its application to on-board emission measurement system, SAE paper 2002-01-0612, (2002).

W. Silvis, J. Williamson, N. Kreft and A. Alajbegovic, DVE — Direct vehicle exhaust flow measurement using headtype flowmeters, SAE paper 2003-01-0782 (2003).

K. I. Kim, W. Y. Yoo and C. H. Lee, A study on flow rate characteristics of a triangular separate bar differential pressure flow meter according to the variation of gas flow temperature, Transactions of the Korean Society of Machine Tool Engineers, 17(4) (2008) 89–94.