@inproceedings{oai:jaxa.repo.nii.ac.jp:00005945,
 author = {Krause, Egon},
 book = {宇宙航空研究開発機構特別資料: 航空宇宙数値シミュレーション技術シンポジウム2006論文集, JAXA Special Publication: Proceedings of Aerospace Numerical Simulation Symposium 2006},
 month = {Dec},
 note = {Two examples of flows dominated by vortical structures are discussed: In the first interaction and decay of vortex structures in in-cylinder flows of automotive engines are described. Numerical studies revealed clearly identifiable vortex rings, generated during the intake stroke. The influence of compressibility on the vortex formation was studied by using Mach-Zehnder interferometry in a specially designed test stand of a towed one-cylinder engine, and with numerical solutions of the Navier-Stokes equations. In an industrial application a stable vortex ring could be generated by direct high-pressure liquid fuel injection, issuing a conical flow of evaporating droplets and stratifying the evaporated fuel to an ignitable air-fuel mixture. This concept led to a substantial reduction of fuel consumption. In the second example the state of the art of investigations aimed at finding means to destabilize tip vortices of aircraft wakes is briefly reviewed. Enforcing a more rapid decay compared to the natural one and reducing the downwash of large aircraft during take-off and landing are presently pursued in several studies. Discussed are the influence of the spanwise position of the engines, of winglets, of preset and oscillating ailerons on the vorticity distribution in the tip vortices and on their destabilization. The results are preliminary in nature. Further investigations in more detail are needed to substantiate previous findings., 資料番号: AA0063154001, レポート番号: JAXA-SP-06-010},
 pages = {1--6},
 publisher = {宇宙航空研究開発機構, Japan Aerospace Exploration Agency (JAXA)},
 title = {Vortical flows in technical applications},
 volume = {JAXA-SP-06-010},
 year = {2006}
}