Pregled bibliografske jedinice broj: 769113
Harmonic Balance Method for Unsteady Periodic Flows
Harmonic Balance Method for Unsteady Periodic Flows // 10th OpenFOAM Workshop
Ann Arbor (MI), Sjedinjene Američke Države, 2015. (predavanje, nije recenziran, pp prezentacija, znanstveni)
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Naslov
Harmonic Balance Method for Unsteady Periodic Flows
Autori
Cvijetić, Gregor ; Jasak, Hrvoje
Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, pp prezentacija, znanstveni
Skup
10th OpenFOAM Workshop
Mjesto i datum
Ann Arbor (MI), Sjedinjene Američke Države, 29.06.2015. - 02.07.2015
Vrsta sudjelovanja
Predavanje
Vrsta recenzije
Nije recenziran
Ključne riječi
Harmonic Balance; Unsteady Periodic Flow; Fourier Series; Scalar Transport; p-U Coupling; OpenFOAM
Sažetak
Harmonic Balance method for unsteady periodic flows is presented in this study. Assumption of a time periodic flow allows us to formulate 2n + 1 coupled steady state problems. By solving 2n + 1 steady state problems, we obtain a transient flow field. Fourier series expansion is the core of the Harmonic Balance method, therefore the accuracy of the method depends on the number of harmonics specified, n. Accuracy of the method also depends on the periodic nature of the problem. The method was first derived for a passive scalar transport and implemented in OpenFOAM. Validation has been carried out on 4 test cases concerning forced periodic behaviour at the inlet of the rectangular 2D domain. The first test case was a sine wave, which was fully resolved with 1 harmonic. The second case was a linear combination of sine and cosine waves with different frequencies, resolved with 2 harmonics. After successful validation of harmonic waves, robustness and accuracy test was carried out on two square waves. Square waves are numerically more difficult and more demanding, which was also shown in the convergence study carried out using 3, 5, 7 and 10 harmonics. Harmonic Balance method results were compared to transient simulation for all of the test cases. After validation of the passive scalar transport, the Harmonic Balance pressure-velocity system was derived and implemented. Preliminary validation of NACA2412 pitching airfoil was presented together with performance comparison between transient solver and Harmonic Balance.
Izvorni jezik
Engleski
Znanstvena područja
Strojarstvo
