Turbulent Flow Past Two-Body Configurations

Flows Around Bodies

Underlying Flow Regime 2-12

Evaluation

Comparison of CFD Calculations with Experiments

This section is organized as follows. First (Section 6.1), results of some sensitivity studies are presented and briefly discussed. These include evaluation of such effects as span-size of the domain, compressibility, time sample used for computing the mean flow and turbulent statistics, and numerical dissipation of the method used. Then, in Section 6.2, a comparison with the experimental data is shown for the main body of simulations carried out within the ATAAC project with the use of the physical and computational problem setups outlined in Section 5.

RESULTS OF SENSITIVITY STUDIES

Effect of span size of domain

As mentioned in Section 4, the aspect ratio of the CT configuration L_z/ D in the BART facility is equal to 12.4. Strictly speaking this demands carrying out simulations exactly at this value of /L/z//D/ and

   imposing no-slip boundary conditions on the floor and  ceiling  of  the
   test section (see Figure 2). However such  simulations  would  be  very
   expensive. Considering this and, also, recommendations  of  the  BANC-I
   Workshop based on simulations at different /L/z//D/ with periodic  boundary
   conditions in the spanwise directions, most of the simulations  in  the
   ATAAC project were performed at /L/z//D/=3 assuming  spanwise  periodicity.
   In  order  to  get  an  idea  on  how  strong  the  effect  of  such  a
   simplification could be, NTS  conducted  a  series  of  simulations  at
   different  /L/z//D/.  Some  results  of  these  simulations  are  presented
   below[3].

Contributed by: A. Garbaruk, M. Shur and M. Strelets — New Technologies and Services LLC (NTS) and St.-Petersburg State Polytechnic University