DOI QR코드

DOI QR Code

Vortex Features in a Half-ducted Axial Fan with Large Bellmouth (Effect of Tip Clearance)

  • Received : 2009.07.23
  • Accepted : 2011.05.26
  • Published : 2011.09.30

Abstract

In order to clarify the features of tip leakage vortex near blade tip region in a half-ducted axial fan with large bellmouth, the experimental investigation was carried out using a 2-dimensional LDV system. Three sizes of tip clearance (TC) were tested: those sizes were 1mm (0.55% of blade chord length at blade tip), 2mm (1.11% of blade chord length at blade tip) and 4mm (2.22% of blade chord length at blade tip), and those were shown as TC=1mm, TC=2mm and TC=4mm, respectively. Fan characteristic tests and the velocity field measurements were done for each TC. Pressure - flow-rate characteristics and two-dimensional velocity vector maps were shown. The vortex trace and the vortex intensity distribution were also illustrated. As a result, a large difference on the pressure - flow-rate characteristics did not exist for three tip clearance sizes. In case of TC=4mm, the tip leakage vortex was outflow to downstream of rotor was not confirmed at the small and reference flow-rate conditions. Only at the large flow-rate condition, its outflow to downstream of rotor existed. In case of TC=2mm, overall vortex behaviors were almost the same ones in case of TC=4mm. However, the vortex trace inclined toward more tangential direction. In case of TC=1mm, the clear vortex was not observed for all flow-rate conditions.

Keywords

References

  1. Inoue, M., 1997, "Vortex and Turbomachinery," Procs. of 5th Asian International Conference on Fluid Machinery, Seoul (Korea), pp. 117-131.
  2. Lakshminarayana, B., 1970, "Methods of Predicting the Tip Clearance Effects in Axial Flow Turbomachinery," Trans. ASME, Journal of basic Engineering, 92, pp. 467-482. https://doi.org/10.1115/1.3425036
  3. Inoue, M., Kuroumaru, M., Furukawa, M., Kawashima, Y., Shen, W., 1985, "Experimental Study on Tip Leakage Flow in Axial Flow Rotating Blades," Trans. JSME, B, 51-468, pp. 2545-2553(in Japanese). https://doi.org/10.1299/kikaib.51.2545
  4. Fujita, H., 1983, "A Study on Configurations of Casing Treatment for Axial Flow Compressors," Trans. JSME, B, 49-448, pp. 2945-2953(in Japanese). https://doi.org/10.1299/kikaib.49.2945
  5. Furukawa, M., Saiki, K., Yamada, K., Inoue, M., 2000, "Anomalous Flow Phenomena Due to Breakdown of Tip Leakage Vortex in an Axial Compressor Rotor at Near-Stall Condition," Trans. JSME, B, 66-644, pp. 1029-1037 (in Japanese). https://doi.org/10.1299/kikaib.66.1029
  6. Fukano, T., Tukuhara, M., Kawagoe, K., Hara, Y., Kinoshita, K., 1990, "Experimental Study on the Noise Reduction of a Propeller Fan: 1st Report, Aerodynamic Characteristic," Trans. JAMS, B, 56-531, pp. 3378-3382(in Japanese).
  7. Jang. C. M., Furukawa, M., Inoue, M., 2001, "Analysis of Vortical Flow Field in a Propeller- Fan by LDV Measurement and LES - Part 1: Three-Demensional Vortical Flow Structures," Trans. ASME, Journal of Fluids Engineering, 123, pp. 748-754. https://doi.org/10.1115/1.1412565
  8. Kato, C., Shishido, S., Miyazawa, M., Yoshiki, H., Ito, H., Tsubota, H., 2002, "Numerical Prediction of Aerodynamic Noise Radiated from a Propeller Fan," Procs. of 5th JSME-KSME Fluids Engineering Conference, Nagoya(Japan), pp. 522-527.
  9. Cai, W. X., Shiomi, N., Sasaki, K., Kaneko, K., Setoguchi, T., 2002, "Visualization of Tip Vortex Flow in an Open Axial Fan by EFD," Journal of Visualization, 5-3, pp.293-300.
  10. Shiomi, N., Kaneko, K., Cai, W. X., Sasaki, K., Setoguchi, T., 2003, "Tip Vortex Feature in an Open Axial Fan," Turbomachinery, 31-9, 545-553(in Japanese).

Cited by

  1. Effect of Inlet Geometry on Fan Performance and Inlet Flow Fields in a Semi-opened Axial Fan vol.7, pp.2, 2014, https://doi.org/10.5293/IJFMS.2014.7.2.060