{"title":"Low Air Velocity Measurement Characteristics- Variation Due to Flow Regime","authors":"A. Pedi\u0161ius, V. Janu\u0161as, A. Berta\u0161ien\u0117","volume":16,"journal":"International Journal of Mechanical and Mechatronics Engineering","pagesStart":392,"pagesEnd":397,"ISSN":"1307-6892","URL":"https:\/\/publications.waset.org\/pdf\/10051","abstract":"
The paper depicts air velocity values, reproduced by laser Doppler anemometer (LDA) and ultrasonic anemometer (UA), relations with calculated ones from flow rate measurements using the gas meter which calibration uncertainty is ± (0.15 – 0.30) %. Investigation had been performed in channel installed in aerodynamical facility used as a part of national standard of air velocity. Relations defined in a research let us confirm the LDA and UA for air velocity reproduction to be the most advantageous measures. The results affirm ultrasonic anemometer to be reliable and favourable instrument for measurement of mean velocity or control of velocity stability in the velocity range of 0.05 m\/s – 10 (15) m\/s when the LDA used. The main aim of this research is to investigate low velocity regularities, starting from 0.05 m\/s, including region of turbulent, laminar and transitional air flows. Theoretical and experimental results and brief analysis of it are given in the paper. Maximum and mean velocity relations for transitional air flow having unique distribution are represented. Transitional flow having distinctive and different from laminar and turbulent flow characteristics experimentally have not yet been analysed.<\/p>\r\n","references":"[1] Berta\u253c\u00edien\u2500\u00f9 A., Daugel\u2500\u00f9 A., Janu\u253c\u00edas V. Laser Doppler anemometer\r\napplication in the air velocity national standard \/\/ Advances in Heat\r\nTransfer. Proc. of V-th Baltic Heat Transfer Conference. Saint-\r\nPetersburg, September 19-21, 2007. P. 487 - 494.\r\n[2] Janu\u253c\u00edas V., Ilgarubis V., Daugel\u2500\u00f9 A. Oro grei\u2500\u00ecio ver\u2500\u00eci\u253c\u2502 atk\u253c\u00bdrimo tyrimas\r\n\/\/ Matavimai.-2004.- Nr.2 (30). P.11-14.\r\n[3] Berta\u253c\u00edien\u2500\u00f9 A., Daugel\u2500\u00f9 A., Janu\u253c\u00edas V. Investigation of practical\r\napplication of laser Doppler anemometer \/\/ Matavimai. 2006. Nr.2 (38),\r\nP. 5-10.\r\n[4] Euromet Key Comparison M. FF - K3 - Draft A - February, 2008.\r\n[5] Zhukauskas A. Convective transfer in heat exchangers. Science. 1982, p. 472.\r\n[6] H. Schlichting boundary layer theory. Science. 1974 S. 712.\r\n[7] Jakevi\u2500\u00ecius L., Butkus J., Janu\u253c\u00edas V., Ilgarubis V. The influence of\r\nflattened flow profile to the airflow velocity measurement by ultrasound\r\n\/\/ Ultragarsas. 2005. Nr.4(57). P.18-21.","publisher":"World Academy of Science, Engineering and Technology","index":"Open Science Index 16, 2008"}