cfl dt bug fix (#1027)

Co-authored-by: Spencer Bryngelson <[email protected]>

Author: wilfonba

src/simulation/m_sim_helpers.fpp

@@ -277,17 +277,17 @@ contains
                 if (grid_geometry == 3) then
                     fltr_dtheta = f_compute_filtered_dtheta(k, l)
                     vcfl_dt = cfl_target*(min(dx(j), dy(k), fltr_dtheta)**2._wp) &
-                              /minval(1/(rho*Re_l))
+                              /maxval(1/(rho*Re_l))
                 else
                     vcfl_dt = cfl_target*(min(dx(j), dy(k), dz(l))**2._wp) &
-                              /minval(1/(rho*Re_l))
+                              /maxval(1/(rho*Re_l))
                 end if
             elseif (n > 0) then
                 !2D
                 vcfl_dt = cfl_target*(min(dx(j), dy(k))**2._wp)/maxval((1/Re_l)/rho)
             else
                 !1D
-                vcfl_dt = cfl_target*(dx(j)**2._wp)/minval(1/(rho*Re_l))
+                vcfl_dt = cfl_target*(dx(j)**2._wp)/maxval(1/(rho*Re_l))
             end if
         end if