TY - GEN
T1 - Scaling of flow characteristics and power consumption with profile height for miniature centrifugal fans
AU - Walsh, P. A.
AU - Egan, V.
AU - Grimes, R.
AU - Walsh, E.
PY - 2007
Y1 - 2007
N2 - This paper addresses issues that relate to downscaling the height of centrifugal fans for application in low profile technologies, such as the cooling of portable power electronics. The parameters studied throughout the paper include flow rate, pressure rise and power consumption characteristics. The former two of these are measured using a fan characterization rig and the latter by directly measuring the power supplied to the fan. These are studied for fans ranging in diameter from 15 to 30mm and with profile heights ranging from 0.3mm to 15mm. It is found that all of the phenomena encountered are best described in terms of fan aspect ratio. Overall, the results show that the conventional scaling laws cannot be accurately applied when the blade profile alone is being scaled. Indeed the only parameter that was observed to be accurately predicted by the scaling laws was the pressure rise attainable but was only accurate for fan aspect ratios greater than 0.17. Below this, the measured pressure rise characteristics fell logarithmically toward zero. The results also showed that there is no advantage to using fans with aspect ratio greater than 0.3. This was because the maximum flow rate was achieved at this aspect ratio and decreased slightly as it was further increased. Overall, the scaling phenomena described throughout this paper are invaluable to designer of efficient low profile cooling solutions that are to incorporate such fans.
AB - This paper addresses issues that relate to downscaling the height of centrifugal fans for application in low profile technologies, such as the cooling of portable power electronics. The parameters studied throughout the paper include flow rate, pressure rise and power consumption characteristics. The former two of these are measured using a fan characterization rig and the latter by directly measuring the power supplied to the fan. These are studied for fans ranging in diameter from 15 to 30mm and with profile heights ranging from 0.3mm to 15mm. It is found that all of the phenomena encountered are best described in terms of fan aspect ratio. Overall, the results show that the conventional scaling laws cannot be accurately applied when the blade profile alone is being scaled. Indeed the only parameter that was observed to be accurately predicted by the scaling laws was the pressure rise attainable but was only accurate for fan aspect ratios greater than 0.17. Below this, the measured pressure rise characteristics fell logarithmically toward zero. The results also showed that there is no advantage to using fans with aspect ratio greater than 0.3. This was because the maximum flow rate was achieved at this aspect ratio and decreased slightly as it was further increased. Overall, the scaling phenomena described throughout this paper are invaluable to designer of efficient low profile cooling solutions that are to incorporate such fans.
UR - http://www.scopus.com/inward/record.url?scp=37249078623&partnerID=8YFLogxK
U2 - 10.1115/ICNMM2007-30136
DO - 10.1115/ICNMM2007-30136
M3 - Conference contribution
AN - SCOPUS:37249078623
SN - 079184272X
SN - 9780791842720
T3 - Proceedings of the 5th International Conference on Nanochannels, Microchannels and Minichannels, ICNMM2007
SP - 237
EP - 244
BT - Proceedings of the 5th International Conference on Nanochannels, Microchannels and Minichannels, ICNMM2007
T2 - 5th International Conference on Nanochannels, Microchannels and Minichannels, ICNMM2007
Y2 - 18 June 2007 through 20 June 2007
ER -