<reponame>MarioKrenn6240/SEMNET
{"id":"10.1103/PhysRevFluids.1.024404","title":{"value":"Space-time characteristics of wall-pressure and wall shear-stress fluctuations in wall-modeled large eddy simulation","format":"html+mathml"},"publisher":{"name":"APS"},"journal":{"id":"PRFLUIDS","abbreviatedName":"Phys. Rev. Fluids","name":"Physical Review Fluids"},"issue":{"number":"2"},"volume":{"number":"1"},"pageStart":"024404","hasArticleId":true,"date":"2016-06-20","numPages":17,"articleType":"article","identifiers":{"doi":"10.1103/PhysRevFluids.1.024404"},"rights":{"rightsStatement":"©2016 American Physical Society","copyrightYear":2016,"copyrightHolders":[{"name":"American Physical Society"}]},"authors":[{"type":"Person","name":"<NAME>","firstname":"<NAME>","surname":"Park","affiliationIds":["a1"]},{"type":"Person","name":"<NAME>","firstname":"Parviz","surname":"Moin","affiliationIds":["a1"]}],"affiliations":[{"id":"a1","name":"Center for Turbulence Research, Stanford University, 488 Escondido Mall, Stanford, California 94305-4035, USA"}],"abstract":{"value":"<p>We report the space-time characteristics of the wall-pressure fluctuations and wall shear-stress fluctuations from wall-modeled large eddy simulation (WMLES) of a turbulent channel flow at <span class=\"aps-inline-formula\"><math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub><mtext>Re</mtext><mi>τ</mi></msub><mo>=</mo><mn>2000</mn></math></span>. Two standard zonal wall models (equilibrium stress model and nonequilibrium model based on unsteady RANS) are employed, and it is shown that they yield similar results in predicting these quantities. The wall-pressure and wall shear-stress fields from WMLES are analyzed in terms of their r.m.s. fluctuations, spectra, two-point correlations, and convection velocities. It is demonstrated that the resolution requirement for predicting the wall-pressure fluctuations is more stringent than that for predicting the velocity. At least <span class=\"aps-inline-formula\"><math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>δ</mi><mo>/</mo><mi mathvariant=\"normal\">Δ</mi><mi>x</mi><mo>&gt;</mo><mn>20</mn></mrow></math></span> and <span class=\"aps-inline-formula\"><math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mi>δ</mi><mo>/</mo><mi mathvariant=\"normal\">Δ</mi><mi>z</mi><mo>&gt;</mo><mn>30</mn></mrow></math></span> are required to marginally resolve the integral length scales of the pressure-producing eddies near the wall. Otherwise, the pressure field is potentially aliased. Spurious high wave number modes dominate in the streamwise direction, and they contaminate the pressure spectra leading to significant overprediction of the second-order pressure statistics. When these conditions are met, the pressure statistics and spectra at low wave number or low frequency agree well with the DNS and experimental data. On the contrary, the wall shear-stress fluctuations, modeled entirely through the RANS-based wall models, are largely underpredicted and relatively insensitive to the grid resolution. The short-time, small-scale near-wall eddies, which are neither resolved nor modeled adequately in the wall models, seem to be important for accurate prediction of the wall shear-stress fluctuations.</p>","format":"html+mathml"},"classificationSchemes":{"physh":{"disciplines":[{"id":"512fd433-7b6d-4535-bb60-78f3bf431bc3","label":"Fluid Dynamics"}],"concepts":[{"id":"0c2f74cc-42b0-4b3a-b470-cd50aa7d0f89","label":"Boundary layers","facet":{"id":"bdb1ef91-b776-4e36-8f8f-3e93666bac1e","label":"Research Areas"}},{"id":"062f0300c33d4782b24c43996b0469f3","label":"Turbulence","facet":{"id":"bdb1ef91-b776-4e36-8f8f-3e93666bac1e","label":"Research Areas"},"primary":true}]}}}