At the 21:00 mark when you take about the slope of theta, you say that it gets steeper (larger) near the leading edge. Should it be larger away from the leading edge? Or am I misunderstanding?
At 24:00 mark you summarize the VBL and show the VBL diagram with the two slopes. Why does the left one say "very steep" but the one on the right has a steeper slope?
vel in x-direction is "u" and it is a function of "y" distance from the plate into the fluid. "very steep" means du/dy is larger, so velocity rapidly increases going into the fluid from the plate surface.
think of an exponential function(the graph of one). it starts at a value, and rapidly turns into an asymptote. where the slope is infinity where it starts, and zero where it finishes for a horizontal asymptote, and vice versa for a vertical asymptote. You can see there are two plots with one of each type in the same picture so consider which one youre analyzing. The blue lines he has drawn on both analogous plots are just that. we know that the slope of a flat line is just zero.. so just imagine that the plate on the right is hot, and there is fluid flowing over it. At the knife edge(leading edge) right where the fluid first comes into contact, the plate doing the heating hasn't had a chance to do an even heating, since most of the plate lies to the right of that point. But further down the line, where the plate has heated more of the fluid, the fluids temperature will be constant at any y location you choose to analyze. where the temperature at y=0 is just the temp of the plate, and it decreases temperature as you move away from the plate(heat source). But the whole concept here is that there is a point where the temperature stops decreasing as you move away from the plate. in other words, it is approaching some value(the asymptote). and since temperature obviously wont get below T(infinity), we can say that our temperature as a function of y [T(y)] must lie somewhere between the surface temperature, and the freestream fluid temperature. How far between these temperatures does it lie? that's your theta. look up the formula for linear interpolation and it will look exactly like that. theta lies between zero and one. and depends on where you are in the y location which varies of 0 to delta
b careful because there are two exponential profiles on the same plot. one representing the fluid temperature as a function of y. and one plotting the delta, which is the depth of effect due to the prescence of the plate
This is really good for concept understandining. In my class, the prof only explain abt the equation. thank you!
HUGE help! Thank you!
Best prof ever.
Omg thanks!!!
Will the heat flux going into the plate remain same throughout the length of the plate or will it be a function of x ? ( same for dT/dy )
"you can take it out" at 10:00 scared me out
LOL it got another victim
At the 21:00 mark when you take about the slope of theta, you say that it gets steeper (larger) near the leading edge. Should it be larger away from the leading edge? Or am I misunderstanding?
At 24:00 mark you summarize the VBL and show the VBL diagram with the two slopes. Why does the left one say "very steep" but the one on the right has a steeper slope?
vel in x-direction is "u" and it is a function of "y" distance from the plate into the fluid. "very steep" means du/dy is larger, so velocity rapidly increases going into the fluid from the plate surface.
Thank you. I get it now.
think of an exponential function(the graph of one). it starts at a value, and rapidly turns into an asymptote. where the slope is infinity where it starts, and zero where it finishes for a horizontal asymptote, and vice versa for a vertical asymptote. You can see there are two plots with one of each type in the same picture so consider which one youre analyzing.
The blue lines he has drawn on both analogous plots are just that. we know that the slope of a flat line is just zero..
so just imagine that the plate on the right is hot, and there is fluid flowing over it. At the knife edge(leading edge) right where the fluid first comes into contact, the plate doing the heating hasn't had a chance to do an even heating, since most of the plate lies to the right of that point. But further down the line, where the plate has heated more of the fluid, the fluids temperature will be constant at any y location you choose to analyze. where the temperature at y=0 is just the temp of the plate, and it decreases temperature as you move away from the plate(heat source).
But the whole concept here is that there is a point where the temperature stops decreasing as you move away from the plate. in other words, it is approaching some value(the asymptote). and since temperature obviously wont get below T(infinity), we can say that our temperature as a function of y [T(y)] must lie somewhere between the surface temperature, and the freestream fluid temperature.
How far between these temperatures does it lie? that's your theta. look up the formula for linear interpolation and it will look exactly like that.
theta lies between zero and one. and depends on where you are in the y location which varies of 0 to delta
b careful because there are two exponential profiles on the same plot. one representing the fluid temperature as a function of y. and one plotting the delta, which is the depth of effect due to the prescence of the plate