Pressure distribution on a circular cylinder in cross flow with blowing


Azeez, Saleem




An experimental study of the pressure distribution around a circular cylinder in cross flow with blowing has been carried out in this investigation. Three cylinders of 2 in. O.D. and of different roughnesses were tested. Two solid cylinders were also tested to study the effects of blowing in relation to non blown cylinders. The Reynolds number ranged from 0.3 x 105 to 1.08 x 10s for the blown cylinders while for the solid cylinders it ranged from 0.3 x 105 to 2.39 x 10s. The dimensionless blowing parameter varied from 0.4 to 7.3 while the roughness coefficient (k A) ranged from 0.5 x 10~5 to 27.5 x 10~5. The data obtained was corrected for static pressure hole error and wind tunnel wall interference effects. The dimensionless pressure coefficient C has been P presented in graphical form as a function of the angular location. Comparison of the pressure distribution with blowing, with that of no blowing indicates that blowing alters the pressure distribution considerably, the deviation being largest near the region of minimum pressure. The higher the blowing rate, the larger is the deviation of the pressure distribution from that of a solid cylinder. At high blowing rates the point of minimum pressure moved towards the rear stagnation point and the adverse pressure gradient was small or almost absent, the entire flow tending towards supercritical. Roughness did not have any significant effect on the pressure distribution with or without blowing in the subcritical range. In the critical range the rough solid cylinder (k ,, = 27.5 x 10"5) underwent transition before separation at s/d Re^ = 2.39 x 10s, while the smooth solid cylinder (k /d = 0.5 x 10' still separated laminarly at Re^ = 2.27 x 10s. The drag coefficient CD calculated from the pressure distribution was found to decrease with blowing, the effect being slight.


Cylinders -- Testing
Drag (Aerodynamics)
Mass Transfer




Carleton University

Thesis Degree Name: 

Master of Engineering: 

Thesis Degree Level: 


Thesis Degree Discipline: 

Engineering, Mechanical.

Parent Collection: 

Theses and Dissertations

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