Abstract
The intrinsically unsteady heat transfer on the surface of a cylinder in crossflow has been investigated in detail by numerical simulation as a function of the freestream turbulence intensity and the Reynolds number. After a brief startup transient, a periodic steady state is established at all circumferential locations. The resulting timewise fluctuations were seen to be of different phase depending on where on the circumference they occur. On one side of the cylinder, maxima occurred at the same moment in time as minima occurred on the other side. This finding and comparisons of the magnitudes of the local heat transfer coefficients showed that side-to-side symmetry does not prevail in the presence of the unsteadiness. The fluctuation frequencies were found to be virtually uniform over the entire circumference of the cylinder and varied only slightly with the Reynolds number and the turbulence intensity. The full slate of results included: (a) timewise and circumferential variations of the local heat transfer coefficient, (b) timewise variations of the all-angle spatial-averaged heat transfer coefficient, (c) spatial variations of the timewise-averaged heat transfer coefficient, (d) spatial- and timewise-averaged heat transfer coefficients as a function of turbulence intensity and Reynolds number, (e) timewise fluctuation frequencies, (f) comparisons with the experimental literature, and (g) effect of the selected turbulence model. As expected, the magnitude of the heat transfer coefficient increases as the turbulence intensity increases.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 613-621 |
| Number of pages | 9 |
| Journal | International Journal of Heat and Mass Transfer |
| Volume | 113 |
| DOIs | |
| State | Published - Jan 1 2017 |
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Keywords
- CFD
- Cylinder in crossflow
- Heat transfer
- Nusselt correlation
- Turbulence intensity
Cite this
Turbulence intensity effects on heat transfer and fluid-flow for a circular cylinder in crossflow. / Ahn, J.; Sparrow, Ephraim M; Gorman, John M.
In: International Journal of Heat and Mass Transfer, Vol. 113, 01.01.2017, p. 613-621.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Turbulence intensity effects on heat transfer and fluid-flow for a circular cylinder in crossflow
AU - Ahn, J.
AU - Sparrow, Ephraim M
AU - Gorman, John M
PY - 2017/1/1
Y1 - 2017/1/1
N2 - The intrinsically unsteady heat transfer on the surface of a cylinder in crossflow has been investigated in detail by numerical simulation as a function of the freestream turbulence intensity and the Reynolds number. After a brief startup transient, a periodic steady state is established at all circumferential locations. The resulting timewise fluctuations were seen to be of different phase depending on where on the circumference they occur. On one side of the cylinder, maxima occurred at the same moment in time as minima occurred on the other side. This finding and comparisons of the magnitudes of the local heat transfer coefficients showed that side-to-side symmetry does not prevail in the presence of the unsteadiness. The fluctuation frequencies were found to be virtually uniform over the entire circumference of the cylinder and varied only slightly with the Reynolds number and the turbulence intensity. The full slate of results included: (a) timewise and circumferential variations of the local heat transfer coefficient, (b) timewise variations of the all-angle spatial-averaged heat transfer coefficient, (c) spatial variations of the timewise-averaged heat transfer coefficient, (d) spatial- and timewise-averaged heat transfer coefficients as a function of turbulence intensity and Reynolds number, (e) timewise fluctuation frequencies, (f) comparisons with the experimental literature, and (g) effect of the selected turbulence model. As expected, the magnitude of the heat transfer coefficient increases as the turbulence intensity increases.
AB - The intrinsically unsteady heat transfer on the surface of a cylinder in crossflow has been investigated in detail by numerical simulation as a function of the freestream turbulence intensity and the Reynolds number. After a brief startup transient, a periodic steady state is established at all circumferential locations. The resulting timewise fluctuations were seen to be of different phase depending on where on the circumference they occur. On one side of the cylinder, maxima occurred at the same moment in time as minima occurred on the other side. This finding and comparisons of the magnitudes of the local heat transfer coefficients showed that side-to-side symmetry does not prevail in the presence of the unsteadiness. The fluctuation frequencies were found to be virtually uniform over the entire circumference of the cylinder and varied only slightly with the Reynolds number and the turbulence intensity. The full slate of results included: (a) timewise and circumferential variations of the local heat transfer coefficient, (b) timewise variations of the all-angle spatial-averaged heat transfer coefficient, (c) spatial variations of the timewise-averaged heat transfer coefficient, (d) spatial- and timewise-averaged heat transfer coefficients as a function of turbulence intensity and Reynolds number, (e) timewise fluctuation frequencies, (f) comparisons with the experimental literature, and (g) effect of the selected turbulence model. As expected, the magnitude of the heat transfer coefficient increases as the turbulence intensity increases.
KW - CFD
KW - Cylinder in crossflow
KW - Heat transfer
KW - Nusselt correlation
KW - Turbulence intensity
UR - http://www.scopus.com/inward/record.url?scp=85020162671&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85020162671&partnerID=8YFLogxK
U2 - 10.1016/j.ijheatmasstransfer.2017.05.131
DO - 10.1016/j.ijheatmasstransfer.2017.05.131
M3 - Article
AN - SCOPUS:85020162671
VL - 113
SP - 613
EP - 621
JO - International Journal of Heat and Mass Transfer
JF - International Journal of Heat and Mass Transfer
SN - 0017-9310
ER -