Volume 2, Issue 4, December 2016, Page: 37-46
Experimental Investigation of Pulsating Turbulent Flow Through Diffusers
Masaru Sumida, Department of Mechanical Engineering, Faculty of Engineering, Kindai University, Higashi-Hiroshima, Japan
Received: Nov. 29, 2016;       Accepted: Dec. 26, 2016;       Published: Jan. 16, 2017
DOI: 10.11648/j.ijfmts.20160204.12      View  2603      Downloads  105
This paper presents the results of an experimental study on a pulsating turbulent flow through conical diffusers with total divergence angles (2θ) of 12, 16, and 24, whose inlet and exit were connected to long straight pipes. To examine the effects of the divergence angle and the nondimensional frequency on flow characteristics, experiments were systematically conducted using a hot-wire anemometry and a pressure transducer. Moreover, the pressure rise between the inlet and the exit of the diffuser was analyzed approximately under the assumption of a quasi-steady flow and expressed in the form of simple empirical equations in terms of the time-mean value, the amplitude, and the phase difference from the flow rate variation. The expressions are in good agreement with the experimental results and very useful in practice. With the increase in the Womersley number, α, and 2θ, the sinusoidal change in the phase-averaged velocity, W, with time becomes distorted, and the W distributions show a more complicated behavior. For the flow at α=10 in the diffusers with large 2θ, the distributions of W are depressed on the diffuser axis. In contrast, for the flow at α=20, W has a protruding distribution on the diffuser axis.
Pulsating Flow, Diffuser, Velocity Distribution, Pressure Distribution, Womersley Number, Divergence Angle
To cite this article
Masaru Sumida, Experimental Investigation of Pulsating Turbulent Flow Through Diffusers, International Journal of Fluid Mechanics & Thermal Sciences. Vol. 2, No. 4, 2016, pp. 37-46. doi: 10.11648/j.ijfmts.20160204.12
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