Designing a Couette Cell - Get the Right Shear Gradient

[J4MacDonald]

I believe I have an understanding of the proper design for a Couette cell. If I am incorrect, please let me know.

Two concentric cylinders, the internal one rotating, the external one static.

1.) If I have a rotating cylinder with a diameter of 28.64789 mm and a static one with a diameter of 29.64789 mm, then 1000 RPM will produce a shear gradient = 3000/sec

2.) If I have a rotating cylinder with a diameter of 10.0 mm and a static one with a diameter of 11.0 mm, then 2864.789 RPM will produce a shear gradient = 3000/sec

Thank you in advance.

 

[Chestermiller]

I believe I have an understanding of the proper design for a Couette cell. If I am incorrect, please let me know.

Two concentric cylinders, the internal one rotating, the external one static.

1.) If I have a rotating cylinder with a diameter of 28.64789 mm and a static one with a diameter of 29.64789 mm, then 1000 RPM will produce a shear gradient = 3000/sec

2.) If I have a rotating cylinder with a diameter of 10.0 mm and a static one with a diameter of 11.0 mm, then 2864.789 RPM will produce a shear gradient = 3000/sec

Thank you in advance.

The first answer should be about 1000/sec. The 2nd answer is correct.