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aazaad December 13, 2015 15:57

Airship problem
 
Hi
I am trying to simulate a turbulence model of an airship with its length 110m and maximum diameter 39m.
I scaled it by 1/55 i.e its new length is 2m.

simulating it for 10^6 Re no full scale model velocity of 1m/s is deduced to 55m/s of scaled model.

I used SA model with rho= 1.225kg/m cube and viscosity = 1.789 * 10^-5
mesh count
Fluid domain : 492876 cells, 3477636 faces
overset mesh : 438958 cells, 2631941 faces

In case of scaled model ( length 2m) wake can be observed at rear of airship
but when I am scaling mesh by 55 i.e I am simulating it for full scale model with same mesh count , no wake region can be observed(I changed the velocity by 1 m/s to make the Re no same in both the cases.

Can anybody explain why is it so?
what's the problem although the reynolds no is same still the physics is not coming out to be same?


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