Experimental Investigation on Flow Downstream of a Triangular Bluff Body at Different Angles

Document Type : Research Article

Authors

1 Engineering Department, Mechanical Engineering, Ferdowsi University, Mashhad

2 null

Abstract

Study of vortex shedding and flow downstream of a triangular bluff body can be used to design a device for measuring the flow angle, a vortex flowmeter or to calibrate the hot-wire anemometer at low velocities. In this paper, flow velocity, turbulence intensity, and vortex shedding from a 10 mm triangular bluff body have been investigated experimentally using hot-wire anemometer. Results show that the flow angle has little effect on flow velocity distribution and turbulence intensity. However, variations of Strouhal number (St) with respect to the flow angle is large, so that Strouhal number at flow angle of 20 ° has the maximum value of 0.23 and at the angle of 62 °, it has the minimum value of 0.133. To calibrate the hot-wire anemometer, it is necessary to measure flow velocity in addition to the measurement of vortex shedding. Under this condition, if the probe is placed in the region: x/a=2.5 and 2.5<y/a<5.2, vortex intensity will be less than 6%, the velocity will be equal to the free stream velocity, and the vortices will be measurable.

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References

[1] M.A. Ardekani, Air flow measurement in experimental fluid mechanics, Iranian Research Organization on Science and Technology, Tehran, 2014.
[2] R.W. Miller, Flow measurement engineering handbook,  (1983).
[3] H.H. Bruun, Hot-wire anemometry: principles and signal analysis, in, IOP Publishing, 1996.
[4] S. Srikanth, A. Dhiman, S. Bijjam, Confined flow and heat transfer across a triangular cylinder in a channel, International Journal of Thermal Sciences, 49(11) (2010) 2191-2200.
[5] A. Johnstone, M. Uddin, A. Pollard, Calibration of hot-wire probes using non-uniform mean velocity profiles, Experiments in Fluids, 39(3) (2005) 527-534.
[6] A. Kumar De, A. Dalal, Numerical study of laminar forced convection fluid flow and heat transfer from a triangular cylinder placed in a channel, Journal of Heat Transfer, 129(5) (2007) 646-656.
[7] S. Luo, M.G. Yazdani, Y. Chew, T. Lee, Effects of incidence and afterbody shape on flow past bluff cylinders, Journal of wind engineering and industrial aerodynamics, 53.399-375(1994)(3)
[8] O. Zeitoun, M. Ali, A. Nuhait, Convective heat transfer around a triangular cylinder in an air cross flow, International Journal of Thermal Sciences, 50(9) (2011) 1685-1697.
[9] M. Swaminathan, G. Rankin, K. Sridhar, A note on the response equations for hot-wire anemometry, (1986).
[10] M. Ardekani, Hot-wire calibration using vortex shedding, Measurement, 42(5) (2009) 722-729.
Amirkabir Journal of Mechanical Engineering
Volume 53, Issue 1 (Special Issue)
April 2021
Pages 427-436

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