A theory of time-dependent upwelling induced by a spacially- and temporally-varying wind with emphasis on the effects of a seabreeze-landbreeze cycle

Solutions are derived for the velocity field of a model ocean - homogeneous, infinitely deep and wide, and bounded on one side by a vertical wall - resulting from a wind which suddenly starts to blow. This model wind consists of a trade wind and a land-seabreeze, both of which decrease exponentially from shore. These solutions are then analysed for various limiting cases. Due to the linearity ot the model, these solutions are separable and yield for t→ ∞ 1.) steady-state upwelling of about 6 X 10-3 cm/sec within the coastal Ekman layer of width O (50 km) as well as sinking across the width of the trade wind belt and 2.) horizontal and vertical oscilliations of daily period. At 20° the vertical oscillations have amplitudes O (10-2 cm/sec) within the coastal Ekman layer and O (10-3 cm/sec) outside of it. In addition the amplitudes of these oscillations are found to be functions of latitude, exhibiting a resonance point at 30° where the inertial frequency and the land-sea-breeze frequency are the same. lt is postulated that the "unbounded" wave energy around 30° is transfered to the turbulent field resulting in increased mixing by 30°. This could possibly explain the relative temperature minima observed there

Annual Research Briefs, 1992

This report contains the 1992 annual progress reports of the Research Fellows and students of the Center for Turbulence Research. Considerable effort was focused on the large eddy simulation technique for computing turbulent flows. This increased activity has been inspired by the recent predictive successes of the dynamic subgrid scale modeling procedure which was introduced during the 1990 Summer Program. Several Research Fellows and students are presently engaged in both the development of subgrid scale models and their applications to complex flows. The first group of papers in this report contain the findings of these studies. They are followed by reports grouped in the general areas of modeling, turbulence physics, and turbulent reacting flows. The last contribution in this report outlines the progress made on the development of the CTR post-processing facility

Annual Research Briefs

This report contains the 1997 annual progress reports of the research fellows and students supported by the Center for Turbulence Research (CTR). Titles include: Invariant modeling in large-eddy simulation of turbulence; Validation of large-eddy simulation in a plain asymmetric diffuser; Progress in large-eddy simulation of trailing-edge turbulence and aeronautics; Resolution requirements in large-eddy simulations of shear flows; A general theory of discrete filtering for LES in complex geometry; On the use of discrete filters for large eddy simulation; Wall models in large eddy simulation of separated flow; Perspectives for ensemble average LES; Anisotropic grid-based formulas for subgrid-scale models; Some modeling requirements for wall models in large eddy simulation; Numerical simulation of 3D turbulent boundary layers using the V2F model; Accurate modeling of impinging jet heat transfer; Application of turbulence models to high-lift airfoils; Advances in structure-based turbulence modeling; Incorporating realistic chemistry into direct numerical simulations of turbulent non-premixed combustion; Effects of small-scale structure on turbulent mixing; Turbulent premixed combustion in the laminar flamelet and the thin reaction zone regime; Large eddy simulation of combustion instabilities in turbulent premixed burners; On the generation of vorticity at a free-surface; Active control of turbulent channel flow; A generalized framework for robust control in fluid mechanics; Combined immersed-boundary/B-spline methods for simulations of flow in complex geometries; and DNS of shock boundary-layer interaction - preliminary results for compression ramp flow

Third International Conference on Inverse Design Concepts and Optimization in Engineering Sciences (ICIDES-3)

Papers from the Third International Conference on Inverse Design Concepts and Optimization in Engineering Sciences (ICIDES) are presented. The papers discuss current research in the general field of inverse, semi-inverse, and direct design and optimization in engineering sciences. The rapid growth of this relatively new field is due to the availability of faster and larger computing machines

Spinful Algorithmization of High Energy Diffraction

High energy diffraction probes fundamental interactions, the vacuum, and quantum mechanically coherent matter waves at asymptotic energies. In this work, we algorithmize our abstract ideas and develop a set of rigid rules for diffraction. To get spin under control, we construct a new Monte Carlo simulation engine, GRANIITTI. It is the first event generator with custom spin-dependent scattering amplitudes for the glueball domain semi-exclusive diffraction, driven by fully multithreaded importance sampling and written in C++. Our simulations provide new computational evidence that the enigmatic glueball filter observable is a spin polarization filter for tensor resonances. For algorithmic spin studies, we automate the classic Laplace spherical harmonics inverse expansion, carefully define the geometric acceptance related phase space issues and study the harmonic mixing properties systematically in different Lorentz frames. To improve the big picture, we generalize the standard soft diffraction observables and definitions by developing a high dimensional probabilistic framework based on incidence algebras, Combinatorial Superstatistics, and solve also a new superposition inverse problem using the Möbius inversion theorem. For inverting stochastic autoconvolution integral equations or `inverting the proton', we develop a novel recursive inverse algorithm based on the Fast Fourier Transform and relative entropy minimization. The first algorithmic inverse results of the proton double multiplicity structure and multiparton interaction rates are obtained using the published LHC data, in agreement with standard phenomenology. For optimal inversion of the detector efficiency response, we build the first Deep Learning based solution working in higher phase space dimensions, DeepEfficiency, which inverts the detector response on an event-by-event basis and minimizes the event generator dependence. Using the ALICE experiment proton-proton data at the LHC at 13 TeV, we obtain the first unfolded fiducial measurement of the multidimensional combinatorial partial cross sections, the first multidimensional maximum likelihood fit of the effective soft pomeron intercept and the first multidimensional maximum likelihood fit of the single, double and non-diffractive component cross sections. Great care is taken with the fiducial and non-fiducial definitions. The second topic of measurements centers on semi-exclusive central diffractive production of hadron pairs, which we study with the ALICE data. We measure and fit the resonance spectra of identified pion and kaon pairs, which is crucial on the road towards solving the mysteries of glueballs, the proton structure fluctuations, and the pomeron.Suurenergiadiffraktio heijastelee luonnon perusvuorovaikutuksia, tyhjiötä ja kvanttimekaanisesti koherentteja aaltoja asymptoottisen suurilla energioilla. Tässä työssä teen abstrakteista ideoista algoritmeja ja kehitän joukon täsmällisiä sääntöjä suurenergiadiffraktiolle. Jotta spin ja kulmaliikemäärä saadaan haltuun, rakennan uuden avoimen lähdekoodin Monte Carlo -simulaatiokoneiston nimeltään GRANIITTI. Se on ensimmäinen törmäysgeneraattori, joka kykenee mallintamaan kattavasti spin-riippuvia relativistisia sironta-amplitudeja keskeisdiffraktion prosesseissa. Näitä hiukkassimulaatioita tarvitaan esimerkiksi CERN:in LHC-kiihdyttimellä tehtävissä kokeissa, joissa keskitytään niin kutsuttujen ”liimapallojen” (eng. glueballs) löytämiseen. Liimapallot ovat vahvan vuorovaikutuksen gluonihiukkasten muodostamia resonoivia kvanttitiloja, joilla on teoreettinen yhteys suurenergiadiffraktioon, mutta joita ei ole saatu kokeellisesti vielä yksikäsitteisesti havaittua. Tämä johtuu niiden monikomponenttiliiman kaltaisesta kvanttitilasta, jossa mukana voi olla myös kvarkkeja. Simulaatioiden avulla löydän uutta laskennallista todistetta sille, että liimapallosuotimena tunnettua arvoituksellista observaabelia ajaa resonanssien spin-polarisaatiotiheys. Suurena tavoitteena on kehittää suurenergiadiffraktion kokonaiskuvaa. Tätä varten esittelen uuden matemaattisen koneiston perustuen todennäköisyyslaskentaan ja kombinatorisiin insidenssialgebroihin. Kutsun tätä kombinatoriseksi superstatistiikaksi. Näin saadaan määriteltyä ja ratkaistua heti uusi inversio-ongelma jo tunnetun Möbius-inversiolauseen avulla. Jatkan inversio-ongelmien saralla ja näytän ensimmäisenä kuinka protoni-protoni -törmäyksissä syntyneiden varattujen hiukkasten todennäköisyysjakauma voidaan algoritmillisesti uudelleenorganisoida. Näin saadaan uusia näkökulmia suurenergiaprotonien monimutkaiseen rakenteeseen ja dynamiikkaan, jossa useat partonit protonin sisältä törmäävät samanaikaisesti. LHC-datan avulla saadut algoritmilliset tulokset ovat samansuuntaisia aiempien mallipohjaisten tulkintojen kanssa. Kehitän myös ensimmäisenä algoritmin, joka syväkorjaa lähes optimaalisesti mittauslaitteiston tehokkuusvasteen moniulotteisessa liikemääräavaruudessa törmäys törmäykseltä. Tämä algoritmi perustuu syviin neuroverkkoihin. Työn kokeellisessa osuudessa hyödynnetään työssä kehitettyjä menetelmiä ja algoritmeja LHC:n ALICE-kokeessa, käyttäen LHC-kiihdyttimen tuottamaa protoni-protoni -törmäysdataa 13 TeV:n massakeskipiste-energialla. Näin tehdään ensimmäinen kokonaisvaltainen pehmeiden törmäysten moniulotteinen fidusiaalimittaus ja ensimmäinen moniulotteinen diffraktiivisten vaikutusalojen suurimman uskottavuuden fidusiaalianalyysi. Lisäksi analysoidaan diffraktiofenomenologian oleellisia parametreja. Toinen mittausten aihe on keskeisdiffraktio. Työssä mitataan hadroniset resonanssispektrit, joiden tutkiminen vie meidät kohti liimapallojen, protonin fluktuoivan sisärakenteen ja pomeronin salaisuuksien ratkaisuja