Nordita Program on Turbulent boundary layers and Turbulent Combustion (6 April - 28 May 2010)

Final Report

Overall structure of the program

The overall duration was 8 weeks. It started with the FLOW-NORDITA Spring school on TURBULENT BOUNDARY LAYERS (6-9 April 2010), and comprised two conferences: the NORDITA and Linne FLOW Centre Workshop on Turbulent Boundary Layers (29-30 April 2010), and The Nordita Turbulent Combustion Conference (26-28 May 2010). The actual program was subdivided into two parts, one on turbulent boundary layers (first part) and one on turbulent combustion (second part). The total number of participants was 96, and 8 of them were women. Of the 96 participants, 40 came from the Nordic countries. Altogether, 29 people stayed for more than about 3 weeks. Additional funding for the conference was attracted from the Linne Flow Center (FLOW) and the Swedish Science Foundation (VR).

During the program we had 18 talks in the first part and 16 in the second part; see the list of Talks at Nordita Programs. Out of these talks, we had one per week that was advertised more broadly within KTH and Nordita. In addition, there were 33 talks during the first conference and 28 during the second conference.

Scientific impact so far

• NORDITA-2010-023 On a self-sustained process at large scale in the turbulent channel flow by Yongyun Hwang, Carlo Cossu, Phys. Rev. Lett. 105, 044505 (2010)
• NORDITA-2010-038 A high-order public domain code for direct numerical simulations of turbulent combustion by N. Babkovskaia, N. E. L. Haugen, A. Brandenburg, J. Comp. Phys., 230, 1-12 (2011)
• NORDITA-2010-057 Turbulent front speed in the Fisher equation: dependence on Damkohler number by A. Brandenburg, N. E. L. Haugen, N. Babkovskaia, Phys. Rev. E 83, 016304 (2011)
• NORDITA-2011-006 Detection of the phenomenon of turbulent thermal diffusion in numerical simulations by Haugen, N. E. L., Kleeorin, N., Rogachevskii, I., Brandenburg, A. (2011)
• NORDITA-2011-010 The diagnostic plot - a litmus test for wall bounded turbulence data by P. H. Alfredsson, R. Örlü, Europ. J. Mech. 29, 403 (2010)
• NORDITA-2011-011 Rigorous derivation of an unclosed mean G-equation for statistically 1D premixed turbulent flames by Vladimir A. Sabel'nikov and Andrei N. Lipatnikov, Int. J. Spray Combustion Dynam., 2, 301-324 (2010)
• NORDITA-2011-012 The interaction of high-speed turbulence with flames: Turbulent flame speed by A.Y. Poludnenko and E.S. Oran, Combust. Flame, 158, 301-326 (2011)
• NORDITA-2011-076 Numerical simulation of forced convection over a periodic series of rectangular cavities at low Prandtl number by E. Stalio, D. Angeli, and G.S. Barozzi, Int. J. Heat Fluid Flow, 32, 1014-1023 (2011)
• NORDITA-2011-125 Scaling of normalized mean energy and scalar dissipation rates in a turbulent channel flow by H. Abe and R. A. Antonia, Phys. Fluids 23, 055104 (2011)

Excerpts from selected responses from the participants

• You did a terrific job organizing the NORDITA conference on turbulent combustion, and I thank you again for inviting me. Your meeting provided an excellent way for those of us who are located outside of Europe to interact with the strong team of researchers from within Sweden and Norway, as well as those from France, Germany and other European countries. ... The NORDITA format is the best way to foster these interactions, and I felt that all of my time in Stockholm was well-spent. My wife also thoroughly enjoyed Sweden.
• I also wanted to thank you again for the opportunity to come to Stockholm and to NORDITA. I think it was a very interesting and productive program. As far as I am concerned, several potential collaborations have emerged ... and I have certainly had a number of very illuminating discussions on a variety of topics (especially with regards to the LEM/ODT and the G-equation).
• It was a fruitful experience, and I learned a lot on my PhD subject by sharing with people. We were very interested in the Pencil Code....
• First, let me express my appreciation for the invitation to attend the Turbulent Combustion program at Nordita. For me, it was an amazing chance to visit the very well-known Nordita, meet you, Nils, and many others, and form an overview of what is happening in the turbulent combustion field. Last but not least, I had the chance to enjoy Stockholm in some depth. (I spent much too much time at the Wasa Museum.)
• For us "old-timers," it was fun to get together, sometimes again after many years. It was good to meet people who will be doing this work in the future. ... and I managed to finally find the time to finish the work we started in organizing a Special Issue of ... I had to opportunity to spend more time talking to ..., meet ... after many years, and see ... insulted by ... and see him respond appropriately and maintained his humor and cool. (Good training for him. That was a highlight).

Suggestions for future programs

Within the combustion community, the concept of programs was not known. Many people expressed interest in repeating such an activity some time in the future. (Meanwhile, a corresponding proposal has been submitted to Nordita.)

There are many parallels between turbulent combustion in technical devices and supernovae type 1a. While several of the program participants where familiar with the astrophysical parameter regime and the relevant issues, we could have done better in getting more astronomers to the program. This might be one aspect to think about on future occasions.

Other items

During the meeting, the Pencil Code (http://pencil-code.googlecode.com/; see also NORDITA-2010-038) has been used by a number of people and its usage is now spreading in the combustion community where such a code (DNS, open source) did not exist previously. People in the combustion community have already started using and developing the code further.

Pictures of program participants are available for the second part of the program: