Selimefendigil F.Polifke W.2024-07-222024-07-22201400011452http://akademikarsiv.cbu.edu.tr:4000/handle/123456789/17171A nonlinear, low-order physics-based model for the dynamics of forced convection wall heat transfer in pulsating flow is formulated, based on the proper orthogonal decomposition technique. In a multivariate approach, proper orthogonal decomposition modes are constructed from computational fluid dynamics data for laminar flow and heat transfer over a flat plate in pulsating flow, spanning a range of pulsation frequencies and amplitudes. Then, the conservation equations for mass, momentum, and energy are projected onto the proper orthogonal decomposition modes, such that a system of ordinary differential equations for the modal amplitudes is obtained. The forcing at the inlet is written explicitly in the ordinary differential equations of the low-order model. The contribution of the nonvanishing pressure term resulting from the incompressible Navier-Stokes equation is included with a calibration method. The accuracy and stability of the low-order model are evaluated by comparison with computational fluid dynamics data. Possible applications of this heat source model to the computation of a describing function or the prediction of limit cycle amplitudes of thermoacoustic instabilities are discussed.EnglishComputational fluid dynamicsHeat transferLaminar flowNavier Stokes equationsOrdinary differential equationsPrincipal component analysisConservation equationsFlow and heat transferIncompressible Navier Stokes equationsPhysics-based modelingProper orthogonal decomposition techniquesProper orthogonal decompositionsSystem of ordinary differential equationsThermoacoustic instabilityForced convectionArticle10.2514/1.J051647