Control of Aerodynamic Flows. Delivery Order 0051: Transition Prediction Method Review Summary for the Rapid Assessment Tool for Transition Prediction (RATTraP)

Davis, M. Bruce; Reed, Helen L.; Youngren, Harold; Smith, Brian T.; Bender, Erich

doi:10.21236/ada442886

Cited by 13 publications

(5 citation statements)

References 132 publications

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“…Проблемы адекватного моделирования ЛТП сходны с проблемами адекватного моделирования турбулентности, но значительно менее изучены, несмотря на то что им посвящено большое количество исследований (см., например, работу [1] и библиографию к ней). Со времени публикации работы [1] существенных изменений не произошло: как и ранее, для используемых в инженерных программах алгоритмов необходима параметризация ЛТП [2,3]. Поэтому в данных программах имеется ряд эмпирических параметров, подбираемых для конкретных классов течений с учетом характера возмущений в набегающем потоке, геометрии течения и шероховатости обтекаемой поверхности.…”

Section: Doi: 1015372/pmtf20150503unclassified

“…Шероховатость поверхности. Шероховатость поверхности может приводить к турбулизации потока в ее окрестности [2]. В данном случае, если число Рейнольдса шероховатости Re k > 150, турбулентный клин генерируется непосредственно за этой поверхностью.…”

Section: сценарии перехода к турбулентностиunclassified

“…Описанный e N -метод считается эталонным физическим методом прогнозирования ЛТП в двумерных и трехмерных до-и трансзвуковых течениях, если степень турбулентности набегающего потока является достаточно малой (малошумные и малотурбулентные аэродинамические трубы, летные условия), а стенкагладкой [2]. Этот метод является также одним из основных методов калибровки других моделей перехода при обтекании тел простой формы.…”

Section: инженерные модели лтпunclassified

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Engineering Modeling of the Laminar–turbulent Transition: Achievements and Problems (Review)

2015

PMTF

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Section: Doi: 1015372/pmtf20150503unclassified

Section: сценарии перехода к турбулентностиunclassified

Section: инженерные модели лтпunclassified

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Engineering Modeling of the Laminar–turbulent Transition: Achievements and Problems (Review)

2015

PMTF

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“…An example where both of these approaches have been used for 3-D configurations is the method of Krimmelbein and Krumbein 7 , where the LILO linear stability analysis code 8 has been coupled with the TAU unstructured grid Navier-Stokes flow solver 9 , with the option of running the COCO boundary-layer code 10 to get boundary layer profile information. Another example of the first approach is the RATTraP method 11 that is under development by Lockheed for the Air Force Research Laboratory (AFRL). Each approach has advantages and disadvantages; for example, the direct extraction method avoids the complication of having to link with a boundary layer code, but raises the issue of the proper criteria for determining the edge of a 3-D boundary layer as an integration limit and typically requires a much finer grid than normal to adequately resolve the boundary layer.…”

Section: A Backgroundmentioning

confidence: 99%

Progress Toward Efficient Laminar Flow Analysis and Design

Campbell

Streit

2011

29th AIAA Applied Aerodynamics Conference

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A multi-fidelity system of computer codes for the analysis and design of vehicles having extensive areas of laminar flow is under development at the NASA Langley Research Center. The overall approach consists of the loose coupling of a flow solver, a transition prediction method and a design module using shell scripts, along with interface modules to prepare the input for each method. This approach allows the user to select the flow solver and transition prediction module, as well as run mode for each code, based on the fidelity most compatible with the problem and available resources. The design module can be any method that designs to a specified target pressure distribution. In addition to the interface modules, two new components have been developed: 1) an efficient, empirical transition prediction module (MATTC) that provides n-factor growth distributions without requiring boundary layer information; and 2) an automated target pressure generation code (ATPG) that develops a target pressure distribution that meets a variety of flow and geometry constraints. The ATPG code also includes empirical estimates of several drag components to allow the optimization of the target pressure distribution. The current system has been developed for the design of subsonic and transonic airfoils and wings, but may be extendable to other speed ranges and components. Several analysis and design examples are included to demonstrate the current capabilities of the system.

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“…The transition prediction models implemented in Navier-Stokes solvers can be categorized into algebraic-integral models and transport models (Davis et al, 2005). The first category includes empirical models, approaches based on stability theory using Orr-Sommerfeld equations, and simplified e N stability models.…”

Section: Introductionmentioning

confidence: 99%

Laminar-turbulent transition characteristics of a 3-D wind turbine rotor blade based on experiments and computations

Özçakmak¹,

Madsen

Sørensen³

et al. 2020

Wind Energ. Sci.

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Abstract. Laminar-turbulent transition behavior of a wind turbine blade section is investigated in this study by means of field experiments and 3-D computational fluid dynamics (CFD) rotor simulations. The power spectral density (PSD) integrals of the pressure fluctuations obtained from the high-frequency microphones mounted on a blade section are analyzed to detect laminar-turbulent transition locations from the experiments. The atmospheric boundary layer (ABL) velocities and the turbulence intensities (T.I.) measured from the field experiments are used to create several inflow scenarios for the CFD simulations. Results from the natural and the bypass transition models of the in-house CFD EllipSys code are compared with the experiments. It is seen that the bypass transition model results fit well with experiments at the azimuthal positions where the turbine is under wake and high turbulence, while the results from other cases show agreement with the natural transition model. Furthermore, the influence of inflow turbulence, wake of an upstream turbine, and angle of attack (AOA) on the transition behavior is investigated through the field experiments. On the pressure side of the blade section, at high AOA values and wake conditions, variation in the transition location covers up to 44 % of the chord during one revolution, while for the no-wake cases and lower AOA values, variation occurs along a region that covers only 5 % of the chord. The effect of the inflow turbulence on the effective angle of attack as well as its direct effect on transition is observed. Transition locations for the wind tunnel conditions and field experiments are compared together with 2-D and 3-D CFD simulations. In contrast to the suction side, significant difference in the transition locations is observed between wind tunnel and field experiments on the pressure side for the same airfoil geometry. It is seen that the natural and bypass transition models of EllipSys3D can be used for transition prediction of a wind turbine blade section for high-Reynolds-number flows by applying various inflow scenarios separately to cover the whole range of atmospheric occurrences.

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Control of Aerodynamic Flows. Delivery Order 0051: Transition Prediction Method Review Summary for the Rapid Assessment Tool for Transition Prediction (RATTraP)

Cited by 13 publications

References 132 publications

Engineering Modeling of the Laminar–turbulent Transition: Achievements and Problems (Review)

Engineering Modeling of the Laminar–turbulent Transition: Achievements and Problems (Review)

Progress Toward Efficient Laminar Flow Analysis and Design

Laminar-turbulent transition characteristics of a 3-D wind turbine rotor blade based on experiments and computations

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