Closed whoburg closed 8 years ago
I rebased this to squash some commits and force-pushed -- so if anyone happens to have a local copy of the LLhale
branch, you'll need to re-fetch it from the remote.
Unfortunately I lost a few inline comments from @bqpd in the process -- sorry -- I'm a rebase newb.
Noticed from playing with the interactive version:
at rho = 0.449
Variable | Variable Description | Variable Uncertainty | Variable Sensitivity | Contribution to Objective Uncertainty |
---|---|---|---|---|
(C_L^{1.5}/C_D) | power parameter | ±1% | -2.996 | 3% |
P_{non flight} | non-flight power requirement | ±3% | 0.3279 | <1% |
P_{solar} | solar cell output | ±2% | -1.016 | 2% |
\eta_p | motor+prop efficiency | ±10% | -2.996 | 30% |
\eta_{batt} | round-trip battery efficiency | ±10% | -1.016 | 10% |
\eta_{daylight} | winter daylight percentage | ±10% | -1.016 | 10% |
\eta_{sun angle} | average utilization from low sun angles | ±10% | -1.016 | 10% |
\rho | air density | ±10% | -1.498 | 15% |
\rho_{solar} | solar cell area density | ±10% | 1.514 | 15% |
f_{struct} | structural weight fraction, m_struct/m_tot | ±10% | 1.124 | 11% |
g | local earth gravity | ±0% | 4.494 | 0% |
h_{batt} | battery specific energy | ±10% | -2.308 | 23% |
m_{pay} | payload mass | ±50% | 0.6721 | 33% |
t_{batt} | time on battery | ±50% | 2.308 | 115% |
@whoburg, that's obviously a false table above, but might something like that be useful for prioritizing the turning of constants into models?
It's not accurate for large uncertainties, but at least gives a sense of "oh hey we should model solar efficiency more accurately; let's take into account the air temperature"
re: sensitivity table, love it!! This is exactly along the lines of what I've been thinking.
work in progress in sizing a solar-powered UAV planning to convert to modular version before merging