Abstract
Convective heat transfer is associated with the nature of the flow near the streamlined solid. Since flow properties vary quickly, it is important to fix their momentary values. We propose a technique for studying heat transfer and air flow based on combined use of gradient heat flux measurement and PIV. The paper presents velocity fields near a pair of circular cylinders and distribution of heat flux per unit area on the surface of the second cylinder. Both cylinders were heated with saturated water steam at atmospheric pressure, thereby keeping temperature of the cylinders constant. The experiments were carried out in the range of Reynolds numbers from 480 to 29800. Differences in vortex structure, dead-air region’s length etc., and heat transfer are revealed depending on the velocity of free stream and the distance between the cylinders. Use of gradient heat flux sensors allows us to estimate pulsations of heat flux at various points of the second cylinder and compare them with the pictures of instantaneous velocity fields. The results are consistent with data from other authors and show the prospects of the proposed methodology.
Highlights
Flow around pipes is a classic problem of hydrodynamics
These comprehensive techniques were used in study of air flow and heat transfer near two circular steam heated cylinders installed in the wind tunnel one after the other
The choice of gradient heat flux sensors (GHFSs) type was due to experimental conditions
Summary
Flow around pipes is a classic problem of hydrodynamics. Today, there are many experimental and computational papers in which the flow and heat transfer for a single tube and a tube row or bundle of various geometry are studied. The authors of [1] managed to obtain distribution of local heat transfer coefficient (HTC) at the surface of a single circular cylinder. They explain the unevenness of HTC value at the surface by the features of flow around bluff solids (presence of laminar-turbulent transition, separated flows, vortexsheet wake formation). In the paper [3], Nakamura et al determined dependence of the average HTC on the angle between the free stream velocity vector and the cylinder generatrix This problem is discussed in [4 – 5], where studies were conducted in different regimes
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
