Numerical Simulation And DPIV Experimental Study On Boundary-layer Flow Control

This paper tracks the latest research trend about the flow control problem at home andabroad, thus a review and analysis about these research and progress in this area isconducted in the following step. Research started with wavy wall as the initial object, thenapplied it to a classic problem in fluid mechanics-flow around the cylinder. on the basis of adeep understanding of the theoretical knowledge about flow around the cylinder and what isCFD, work is done by numerical simulation and PIV experiment,trying to compare thedifference between wavy wall and smooth cylindrical in the respect of the wake field andforce analysis. After, I studied that the different flow velocity effect on the velocity of wavywall. Above all, specific work and main findings of the thesis are as follows:1) A comprehensive review and analysis about the advance of the flow control problemresearch at home and abroad is performed and find the different between all the controlmethods. By finding the deficiencies in the present research results and the necessaryin-depth study of the issue, cleared the research object of this article is cylinder with atravelling wavy wall.2) This paper uses the numerical calculation software Fluent combined withself-programming method to simulate the movement of2D cylinder with a travelling wavywall. Studied the wake flow field and stress distribution of cylinder under different velocityof wavy wall when Re is500and Re is12500. The results showed as follows:With the rise of the wavy wall velocity, the velocity of fluid in the cylinder wake fieldincreases and the resistance decreases. when Re is500,the vortex street in wake fieldcompletely disappeared after the wave velocity reaching4times to incoming flow velocity,and we can get the negative value when the wave velocity exceeding5times to incomingflow velocity. when Re is12500,the vortex street in wake field completely disappearedafter the wave velocity reaching1times to incoming flow velocity, and we can get thenegative value when the wave velocity exceeding2times to incoming flow velocity. Thecylinder ’s lift curve and drag curve appeared irregular high frequency oscillation under twokinds of Reynolds number.3) Construct a three dimensional calculation model of cylinder with a travelling wavywall.Studied the wake flow field and stress distribution of cylinder under different velocityof wavy wall when Re is12500. The results showed as follows: The phenomenon in keeping with the2D results basically. The difference is that lift curve does not appear highfrequency oscillation, just stabled at zero. Resistance curve still appear high frequencyoscillation.4) According to the numerical simulation model, the author uses CAD and Solidworkssoftware design the experimental facility of cylinder with a travelling wavy wall. Choosedthe appropriate materials for processing, and using VB to control the wave velocity.5) This paper studied the difference between wavy wall and smooth cylindrical in therespect of the wake field by means of PIV technology.The Re is12500, the velocity of flowis0.125m/s.And experimented12different speeds of the travelling wavy wall,find thatwavy wall improves the speed of the wake field and bates the vortex shedding frequencies.The effect of wavy wall is proved from the experiment.