Fluidelastic instability of a curved tube array in single phase cross flow

• Published in: Nuclear engineering and technology Vol. 55; no. 3; pp. 1118 - 1124
• Main Authors: Lee, Kang-Hee, Kang, Heung-Seok, Hong, Du-Ho, Kim, Jong-In
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2023; Elsevier; 한국원자력학회
• Subjects: Critical velocity; Curved tube array; Fluidelastic instability; Frequency mismatch; Single phase cross flow; 원자력공학; Curved tube array; Fluidelastic instability; Frequency mismatch; Single phase cross flow; Critical velocity
• ISSN: 1738-5733; 2234-358X
• DOI: 10.1016/j.net.2022.11.007

Experimental study on the fluidelastic instability (FEI) of a curved tube bundle in single phase downward cross flow is investigated for the design qualification and analysis input preparation of helical coiled steam generator tubing. A 6x9 normal square curved tube array with equal and different vertical/horizontal pitch-to-diameter ratio was under-tested up to 6 m/s in term of gap flow velocity to measure the critical velocity for FEI. The critical velocity for FEI was measured at the turning point from the vibration amplitude plot along the gap flow velocity. Our test results were compared with straight tube results and published data in the design guideline. The applicability of the current design guidelines to a curved tube bundle is also assessed. We found that introducing frequency difference in a curved tube array increases the critical velocity for fluidelastic instability.