Open Science Research Excellence

Open Science Index

Commenced in January 2007 Frequency: Monthly Edition: International Publications Count: 31108

Select areas to restrict search in scientific publication database:
Localized and Time-Resolved Velocity Measurements of Pulsatile Flow in a Rectangular Channel
The exploitation of flow pulsation in micro- and mini-channels is a potentially useful technique for enhancing cooling of high-end photonics and electronics systems. It is thought that pulsation alters the thickness of the hydrodynamic and thermal boundary layers, and hence affects the overall thermal resistance of the heat sink. Although the fluid mechanics and heat transfer are inextricably linked, it can be useful to decouple the parameters to better understand the mechanisms underlying any heat transfer enhancement. Using two-dimensional, two-component particle image velocimetry, the current work intends to characterize the heat transfer mechanisms in pulsating flow with a mean Reynolds number of 48 by experimentally quantifying the hydrodynamics of a generic liquid-cooled channel geometry. Flows circulated through the test section by a gear pump are modulated using a controller to achieve sinusoidal flow pulsations with Womersley numbers of 7.45 and 2.36 and an amplitude ratio of 0.75. It is found that the transient characteristics of the measured velocity profiles are dependent on the speed of oscillation, in accordance with the analytical solution for flow in a rectangular channel. A large velocity overshoot is observed close to the wall at high frequencies, resulting from the interaction of near-wall viscous stresses and inertial effects of the main fluid body. The steep velocity gradients at the wall are indicative of augmented heat transfer, although the local flow reversal may reduce the upstream temperature difference in heat transfer applications. While unsteady effects remain evident at the lower frequency, the annular effect subsides and retreats from the wall. The shear rate at the wall is increased during the accelerating half-cycle and decreased during deceleration compared to steady flow, suggesting that the flow may experience both enhanced and diminished heat transfer during a single period. Hence, the thickness of the hydrodynamic boundary layer is reduced for positively moving flow during one half of the pulsation cycle at the investigated frequencies. It is expected that the size of the thermal boundary layer is similarly reduced during the cycle, leading to intervals of heat transfer enhancement.
Digital Object Identifier (DOI):


[1] J. Brodkin, “Bandwidth explosion: As internet use soars, can bottlenecks be averted.” Arstechnica, May 1, 2012. (Online). Available: soars-can-bottlenecks-be-averted/. (Accessed: 2015-11-21).
[2] N. Jeffers, J. Stafford, K. Nolan, B. Donnelly, R. Enright, J. Punch, A. Waddell, L. Erlich, J. O’Connor, A. Sexton, R. Blythman, and D. Hernon, “Microfluidic cooling of photonic integrated circuits (PICs),” in Fourth European Conference on Microfluidics, Limerick, Ireland, 2014.
[3] S. Kandlikar, “Heat transfer mechanisms during flow boiling in microchannels,” in ASME 2003 1st International Conference on Microchannels and Minichannels, pp. 33–46, American Society of Mechanical Engineers, 2003.
[4] T. Persoons, T. Saenen, T. Van Oevelen, and M. Baelmans, “Effect of flow pulsation on the heat transfer performance of a minichannel heat sink,” Journal of Heat Transfer, vol. 134, no. 9, p. 091702, 2012.
[5] G. Stokes, On the effect of the internal friction of fluids on the motion of pendulums, vol. 9. Pitt Press, 1851.
[6] J. Womersley, “Method for the calculation of velocity, rate of flow and viscous drag in arteries when the pressure gradient is known,” The Journal of Physiology, vol. 127, no. 3, pp. 553–563, 1955.
[7] E. Richardson and E. Tyler, “The transverse velocity gradient near the mouths of pipes in which an alternating or continuous flow of air is established,” Proceedings of the Physical Society, vol. 42, no. 1, p. 1, 1929.
[8] T. Sexl, “U¨ ber den von E.G. Richardson entdeckten annulareffekt ,” Zeitschrift f¨ur Physik, vol. 61, no. 5-6, pp. 349–362, 1930.
[9] S. Uchida, “The pulsating viscous flow superposed on the steady laminar motion of incompressible fluid in a circular pipe,” Zeitschrift f¨ur angewandte Mathematik und Physik ZAMP, vol. 7, no. 5, pp. 403–422, 1956.
[10] H. Ito, “Theory of laminar flow through a pipe with non-steady pressure gradients,” Proceedings of the Institute of High Speed Mechanics, p. 163, 1953.
[11] C. Fan and B. Chao, “Unsteady, laminar, incompressible flow through rectangular ducts,” Zeitschrift f¨ur angewandte Mathematik und Physik ZAMP, vol. 16, no. 3, pp. 351–360, 1965.
[12] E. Denison, W. Stevenson, and R. Fox, “Pulsating laminar flow measurements with a directionally sensitive laser velocimeter,” AIChE Journal, vol. 17, no. 4, pp. 781–787, 1971.
[13] J. Harris, G. Peev, and W. Wilkinson, “Velocity profiles in laminar oscillatory flow in tubes,” Journal of Physics E: Scientific Instruments, vol. 2, no. 11, p. 913, 1969.
[14] T. Muto and K. Nakane, “Unsteady flow in circular tube: Velocity distribution of pulsating flow,” Bulletin of JSME, vol. 23, no. 186, pp. 1990–1996, 1980.
[15] D. Eckmann and J. Grotberg, “Experiments on transition to turbulence in oscillatory pipe flow,” Journal of Fluid Mechanics, vol. 222, pp. 329–350, 1991.
[16] M. Spiga and G. Morino, “A symmetric solution for velocity profile in laminar flow through rectangular ducts,” International Communications in Heat and Mass Transfer, vol. 21, no. 4, pp. 469–475, 1994.
Vol:15 No:03 2021Vol:15 No:02 2021Vol:15 No:01 2021
Vol:14 No:12 2020Vol:14 No:11 2020Vol:14 No:10 2020Vol:14 No:09 2020Vol:14 No:08 2020Vol:14 No:07 2020Vol:14 No:06 2020Vol:14 No:05 2020Vol:14 No:04 2020Vol:14 No:03 2020Vol:14 No:02 2020Vol:14 No:01 2020
Vol:13 No:12 2019Vol:13 No:11 2019Vol:13 No:10 2019Vol:13 No:09 2019Vol:13 No:08 2019Vol:13 No:07 2019Vol:13 No:06 2019Vol:13 No:05 2019Vol:13 No:04 2019Vol:13 No:03 2019Vol:13 No:02 2019Vol:13 No:01 2019
Vol:12 No:12 2018Vol:12 No:11 2018Vol:12 No:10 2018Vol:12 No:09 2018Vol:12 No:08 2018Vol:12 No:07 2018Vol:12 No:06 2018Vol:12 No:05 2018Vol:12 No:04 2018Vol:12 No:03 2018Vol:12 No:02 2018Vol:12 No:01 2018
Vol:11 No:12 2017Vol:11 No:11 2017Vol:11 No:10 2017Vol:11 No:09 2017Vol:11 No:08 2017Vol:11 No:07 2017Vol:11 No:06 2017Vol:11 No:05 2017Vol:11 No:04 2017Vol:11 No:03 2017Vol:11 No:02 2017Vol:11 No:01 2017
Vol:10 No:12 2016Vol:10 No:11 2016Vol:10 No:10 2016Vol:10 No:09 2016Vol:10 No:08 2016Vol:10 No:07 2016Vol:10 No:06 2016Vol:10 No:05 2016Vol:10 No:04 2016Vol:10 No:03 2016Vol:10 No:02 2016Vol:10 No:01 2016
Vol:9 No:12 2015Vol:9 No:11 2015Vol:9 No:10 2015Vol:9 No:09 2015Vol:9 No:08 2015Vol:9 No:07 2015Vol:9 No:06 2015Vol:9 No:05 2015Vol:9 No:04 2015Vol:9 No:03 2015Vol:9 No:02 2015Vol:9 No:01 2015
Vol:8 No:12 2014Vol:8 No:11 2014Vol:8 No:10 2014Vol:8 No:09 2014Vol:8 No:08 2014Vol:8 No:07 2014Vol:8 No:06 2014Vol:8 No:05 2014Vol:8 No:04 2014Vol:8 No:03 2014Vol:8 No:02 2014Vol:8 No:01 2014
Vol:7 No:12 2013Vol:7 No:11 2013Vol:7 No:10 2013Vol:7 No:09 2013Vol:7 No:08 2013Vol:7 No:07 2013Vol:7 No:06 2013Vol:7 No:05 2013Vol:7 No:04 2013Vol:7 No:03 2013Vol:7 No:02 2013Vol:7 No:01 2013
Vol:6 No:12 2012Vol:6 No:11 2012Vol:6 No:10 2012Vol:6 No:09 2012Vol:6 No:08 2012Vol:6 No:07 2012Vol:6 No:06 2012Vol:6 No:05 2012Vol:6 No:04 2012Vol:6 No:03 2012Vol:6 No:02 2012Vol:6 No:01 2012
Vol:5 No:12 2011Vol:5 No:11 2011Vol:5 No:10 2011Vol:5 No:09 2011Vol:5 No:08 2011Vol:5 No:07 2011Vol:5 No:06 2011Vol:5 No:05 2011Vol:5 No:04 2011Vol:5 No:03 2011Vol:5 No:02 2011Vol:5 No:01 2011
Vol:4 No:12 2010Vol:4 No:11 2010Vol:4 No:10 2010Vol:4 No:09 2010Vol:4 No:08 2010Vol:4 No:07 2010Vol:4 No:06 2010Vol:4 No:05 2010Vol:4 No:04 2010Vol:4 No:03 2010Vol:4 No:02 2010Vol:4 No:01 2010
Vol:3 No:12 2009Vol:3 No:11 2009Vol:3 No:10 2009Vol:3 No:09 2009Vol:3 No:08 2009Vol:3 No:07 2009Vol:3 No:06 2009Vol:3 No:05 2009Vol:3 No:04 2009Vol:3 No:03 2009Vol:3 No:02 2009Vol:3 No:01 2009
Vol:2 No:12 2008Vol:2 No:11 2008Vol:2 No:10 2008Vol:2 No:09 2008Vol:2 No:08 2008Vol:2 No:07 2008Vol:2 No:06 2008Vol:2 No:05 2008Vol:2 No:04 2008Vol:2 No:03 2008Vol:2 No:02 2008Vol:2 No:01 2008
Vol:1 No:12 2007Vol:1 No:11 2007Vol:1 No:10 2007Vol:1 No:09 2007Vol:1 No:08 2007Vol:1 No:07 2007Vol:1 No:06 2007Vol:1 No:05 2007Vol:1 No:04 2007Vol:1 No:03 2007Vol:1 No:02 2007Vol:1 No:01 2007