My prof is the type who makes up his own questions (rather than pulling them from textbooks). This is his latest work... Anyone got any ideas on how to solve this? He assures me that you don't need velocity or chord or additional info (like Mach numbers) to figure it out and I keep ending up with 3 unknowns with only 1 or 2 equations! Here's the question:
High-performance gliders have very large aspect ratios in order to soar efficiently (for reasons we will discuss later in the course). A 1:30 scale glider model with an aspect ratio of AR=30 is tested in a water tunnel, and found to have a lift coefficient of CL=0.8 at a Reynolds number of Re=2.0*10^6. Based on this result, what is the maximum mass of a full-scale glider, operating in air at the same Reynolds number, that can maintain level flight? Give your answer in kg.
Acceleration due to gravity: g=9.81 m/s^2
For water: ρ=1000 kg/m3 and μ=1.0*10^-5 kg/ms
For air: ρ=1.2 kg/m3 and μ=1.9*10^-5 kg/ms