VISC2 valuse

General scientific issues regarding ROMS

Moderators: arango, robertson

Post Reply
Message
Author
kobl1201
Posts: 60
Joined: Tue Nov 04, 2014 8:29 pm
Location: Kongju National Universty

VISC2 valuse

#1 Unread post by kobl1201 »

Hi~

when i simulated model, which resolution is about 3km, i set visc2 ~ 1m^2/s.

i heard the rule of thumb approximation like this.

visc2 ~ (2*delta_x / pi)**2 / timescale

According to this formaula, when i set the 3km resolution and time scale is 100s, i should set the VISC2 ~ (2*3000/3.14)**2/100s.

it is very large value, i think.

Is it right?? or i have some wrong??

Thank you~

User avatar
kate
Posts: 4088
Joined: Wed Jul 02, 2003 5:29 pm
Location: CFOS/UAF, USA

Re: VISC2 valuse

#2 Unread post by kate »

The time scale is damping time, not the time step. You want to damp at about the growth rate of 2 dx noise.

kobl1201
Posts: 60
Joined: Tue Nov 04, 2014 8:29 pm
Location: Kongju National Universty

Re: VISC2 valuse

#3 Unread post by kobl1201 »

Thank you Kate~

so, the time scale is demermined by myself???

User avatar
kate
Posts: 4088
Joined: Wed Jul 02, 2003 5:29 pm
Location: CFOS/UAF, USA

Re: VISC2 valuse

#4 Unread post by kate »

Yes, feel free to try different values.

Post Reply