Experimental investigation on heat transfer in laminar, transitional and turbulent circular pipe flow with respect to flow regime boundaries

• Published in: International journal of heat and mass transfer Vol. 145; p. 118746
• Main Authors: Bertsche, Dirk, Knipper, Paul, Kapfer, Konstantin, Wetzel, Thomas
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.12.2019; Elsevier BV
• Subjects: Calculation method; Circular pipe flow; Data points; Fluid dynamics; Heat transfer; Heat transfer coefficients; Interpolation; Laminar; Laminar flow; Laminar heat transfer; Pipe flow; Simulation; Transition; Turbulent; Turbulent flow; Transition; Turbulent; Circular pipe flow; Calculation method; Heat transfer; Laminar
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2019.118746

•Validation of Gnielinski’s 2013 calculation method for heat transfer coefficients particularly for 1000 < Re < 4000 and 41 < Pr < 70, where this method has not yet been checked up to now against experimental data.•The flow regime boundaries (laminar, transitional, quasi-transitional and turbulent flow) are evaluated for Prandtl numbers in the range of 13 < Pr < 70 using the method proposed by Everts and Meyer [17]. The empirical prediction methods for heat transfer coefficients in the transition regime between laminar and fully turbulent flow are still subject to changes. This situation reflects a lack of reliable experimental data, which are consistently determined over a wide range of relevant Reynolds and Prandtl numbers. This contribution presents new measurement data, in particular 164 data points for heat transfer coefficients, consistently determined over a wide range of Reynolds and Prandtl numbers, ranging from 13 < Pr < 70 and 375 < Re < 13100. In addition, the widely accepted prediction method for heat transfer in circular pipes according to Gnielinski is tested with the present data and other relevant data from literature. This method relies on a linear interpolation between the heat transfer coefficients at the onset of the transition regime and that of the fully turbulent regime. Consequently, working on a consensus about the values of these onset points is an important issue. In this contribution, the transitional flow regime has been found to start at Recr = 2300, and the fully turbulent flow regime to start in the range of 4100 < Ret < 5400. Those findings support the latest version of Gnielinski’s method, published in 2013, as well as other recent work on the topic, particularly that of Everts and Meyer.