The discussion revolves around calculating surface shear stress in a boundary layer given a specific velocity profile defined by a quadratic equation. Participants are working through a homework problem that involves determining the shear stress based on provided velocity measurements at different distances from the surface.
There is no clear consensus on the correct values for a and b, nor on the resulting shear stress, as participants present differing calculations and results. The discussion remains unresolved with multiple competing views on the approach to the problem.
Participants have not fully detailed their assumptions or the steps taken in their calculations, leading to potential gaps in understanding the relationships between the variables involved.
Students or individuals interested in fluid dynamics, particularly those dealing with boundary layer theory and shear stress calculations.
I have tried the differences of the velocities and distance (du/dy) . Then multiplied it by the dynamic viscosity which came out as 0.36 N/m^2 but the answer is apparently 1.17 N/m^2.Chestermiller said:What have you figured out so far?
You need to solve for a and b from the velocity data; a is the shear rate at the wall.exphaze said:I have tried the differences of the velocities and distance (du/dy) . Then multiplied it by the dynamic viscosity which came out as 0.36 N/m^2 but the answer is apparently 1.17 N/m^2.
I have worked out a = 50000 and substituted to τ*shear rate =μ and this came out as 0.9 N/m^2. I am still stuck.Chestermiller said:You need to solve for a and b from the velocity data; a is the shear rate at the wall.
I get a = 65000/secexphaze said:I have worked out a = 50000 and substituted to τ*shear rate =μ and this came out as 0.9 N/m^2. I am still stuck.
I got it now, Thanks for the advice!Chestermiller said:I get a = 65000/sec