presentation comments MW

[wosnik]

• [ ] some success in onshore wind, ultimatley failure
• [x] I know you like "clean" slides, but add locations of ORPC installations
• [ ] maybe a schematic that explains "one-geometric-parameter" (D) axial turbines and two-paramter CFTs (D, H)
• [ ] maybe have bullet list of what you want to discuss on ORPC and Caltech slides
• [ ] what is the spacing of the Caltech experiments?

  BEM intro, motivation

• [ ] note that F_L and F_D are arbitrary decompositions, also explain F_N and F_T
• [x] BEM: explain dashed horizontal lines in alpha vs theta plot
• [x] add bullets blade-resolving RANS vs. parameterization

  experiment setup

• [ ] Test bed sketch: add backup torque measurement to sketch?
• [x] ADV: less than 1 cm^3 meas.vol.

  UNH RVAT

• [ ] UNH RVAT: should you give solidity in both ways: c/R and Nc/pi D?
• [x] drag is also called thrust. people get confused because "drag" is associated with hydrofoils.
• [ ] "mapping upper half of turbine wake - allowable due to symmetry"
• [ ] resolved velocity in vortex ~20% of U_inf
• [ ] momentum equation: you are really calculating the velocity gradient, not change of momentum in x-direction.
• [x] comment on how small dissipation terms are (can barely see the line) - as expected.

  UNH RVAT Re-Dep

• [ ] details on UNH-RVAT: NACA 0020
• [x] "cheap" --> inexpensive
• [x] explain plots better, e.g. Re_c and Re_D

  RM2

• [x] state solidity of RM2, blade profile, etc. - make sure RM2 is presented in the same way as UNH-RVAT.
• [ ] maybe a comparison table: UNH RVAT vs RM2?
• [ ] give background of reference model project
• [x] RM2 performance, Re-dep: add TSR

  blade-resolved RANS.

• [ ] a bit more background on models k-w SST vs Spalart-Allmaras, 2 vs 1 equations, benefits/drawbacks
• [x] did you ever check on "domain dependence", i.e., extending domain further upstream/downstream?
• [ ] more deatils on boundary conditions
• [ ] how was mean c_P calculated?
• [x] need to identify plots on slides (which model, model vs experiment)
• [ ] near wake momentum transport: could discrepancies be due to domain choice?

  ALM

• [ ] here you give references for the first time.Should you give references in previous sections as well?
• [x] dynamic stall: "hysteresis"
• [x] importance of "force smoothing": is there a physical approach to getting this right?
• [x] "implemented in a k-e model" --> move first two bullets to end. leave a blank line between 5 bullets from ALM and the two last bullet.
• [x] on ALM grid slide: compare ALM mesh to blade resolving mesh, have a small table that compares computational cost savings (do not just say it)
• [x] performance results: label UNH-RVAT and RM2
• [ ] physical model for time constants?
• [ ] ALM results are troubling :-)
• [x] LES vis.: point out that you don't see "blades", only effects of forces...
• [ ] need good physical explanation on why RANS ALM and LES ALM terms end up with wrong signs and significantly different magnitudes
• [ ] some of the issues raised here should go into "future work"

  conclusions

• [x] computational effort for different models overview table
• [ ] quantitative results comparison? prob. not, would get a bit ugly...

  for thesis

• [ ] include CFD model formulations (k-w, S-A, LES)

  general comments

• [x] add some details to slides: some people are "readers", and not so much listeners. Some of teh slides are not "readable" for people who are not familiar with these turbines.
• [ ] should cite open data sets and papers published/submitted.

[petebachant]

I'm thinking about omitting the CFD TKE slides to shave off some time. They don't add a lot to the story, since the turbulence effects on the mean flow (what we really care about) are bundled up in eddy viscosity.

[wosnik]

Ok, I guess.

Move everything you cut to “back-up slides”, since these things may come up in discussion with the committee.

[petebachant]

I am adding the Froude number in there as well. Should I use the tip submergence as the length scale?

[wosnik]

Yes. 2 types of Fr: based on tip submergence (tells you how relevant Fr is to turbine operation (should probably use relative velocity on blade element near tip), and based on channel depth (tells you about flow, energy branch sub/supercritical.