Stagnation Point Heat Transfer to an Axisymmetric Impinging Jet at Transition to Turbulence

0564650 - ÚT 2024 RIV US eng J - Článek v odborném periodiku
Antošová, Zuzana - Trávníček, Zdeněk
Stagnation Point Heat Transfer to an Axisymmetric Impinging Jet at Transition to Turbulence.
ASME Journal of Heat and Mass Transfer. Roč. 145, č. 2 (2023), č. článku 023902. ISSN 2832-8450. E-ISSN 2832-8469
Grant CEP: GA ČR(CZ) GC21-26232J
Institucionální podpora: RVO:61388998
Klíčová slova: impinging jet * heat transfer * pipe nozzle
Obor OECD: Thermodynamics
Způsob publikování: Omezený přístup
https://asmedigitalcollection.asme.org/heattransfer/article/145/2/023902/1146835/Stagnation-Point-Heat-Transfer-to-an-Axisymmetric

A round air jet issuing from a long straight pipe and impinging perpendicularly onto a heated flat plate was investigated experimentally. The Reynolds number (Re) covered the fully laminar, transitional, and fully turbulent regimes-Re = 850-15,400. The main focus of this investigation was the transition regime, which occurred at Re = 2250-3010. Various measurements were recorded during the experiments using a hot-wire anemometer, an infrared thermometer, and a thermopile heat flux sensor, the mass transfer was measured using the naphthalene sublimation technique. The stagnation point heat transfer was correlated to the laminar and turbulent regimes in the form of the stagnation point Nusselt number, Nu(0) = (CRePr0.4)-Pr-m, where the exponent m = 0.50 and 0.55, respectively. The Nu(0)-Re relationship exhibited nonmonotonic behavior (decrease) in the transition regime. Two counteracting mechanisms occur during transition-jet core shortening and an increase in velocity fluctuation, the former reduces Nu(0), whereas the latter increases it.
Trvalý link: https://hdl.handle.net/11104/0342115