Validation of Boundary-Layer-Transition Computations for a Rotor with Axial Inflow

Boundary-layer-transition computations are performed using the in-house finite-volume solvers elsA by ONERA and TAU by DLR. Reynolds-averaged Navier-Stokes simulations, using the Langtry-Menter model as well as semiempirical transition criteria, are presented using both solvers for a rotor in climb. The numerical results are compared to temperature-sensitive paint experiments conducted at DLR's rotor test facility. Concerning the Langtry-Menter computation, transition occurs with both solvers due to laminar separation close to the trailing edge, further downstream than seen in the experiment. Semi-empirical transition criteria predict transition within both codes due to laminar separation, which was not detected in the experiments. When only considering the AHD criterion, the transition locations within the numerical simulations and the experiment are in good agreement along the entire span in all three considered test cases. In addition, numerical results are presented for a test case with cyclic pitch. These unsteady boundary-layer transition computations are carried out using the semi-empirical transition criteria approach of DLR-TAU. In accordance with the static test cases, the results are promising, as long as the laminar-separation criterion is deactivated

Assessment of Boundary Layer Transition Prediction Methods for Rotating Blades

Boundary-layer-transition computations are performed using the in-house finite-volume solvers elsA by ONERA and TAU by DLR. Reynolds-averaged Navier-Stokes simulations, using the Langtry-Menter model as well as semiempirical transition criteria, are presented using both solvers for a rotor in climb. The numerical results are compared to temperature-sensitive paint experiments conducted at DLR's rotor test facility. Concerning the Langtry-Menter computation, transition occurs with both solvers due to laminar separation close to the trailing edge, further downstream than seen in the experiment. The transition locations using AHD semi-empirical transition criterion are in good agreement along the entire span in all three considered test cases. In addition, numerical results are presented for a test case with cyclic pitch. These unsteady boundary-layer transition computations are carried out using the semi-empirical transition criteria approach of DLR-TAU. In accordance with the static test cases, the results are promising, as long as the laminar-separation criterion is deactivated

Main Phase of the ERATO Cooperation on Aeroacoustic Rotor Optimization

This report summarizes major steps and results of the second or main phase of the aeroacoustic rotor optimization programme (ERATO), which was jointly conducted by ONERA and DLR. In order to fulfil the ambitious design goal of 6dB reduction of the BVI impulsive noise during landing approaach compared to the 7AD reference rotor, extensive parametric studies on different rotor and blade design parameters were performed followed by the aeroacoustic optimization process which was based on the results of the parametric studies and on engineering judgement

Wall surface temperature calculation in the SolEdge2D-EIRENE transport code

15th International Conference on Plasma-Facing Materials and Components for Fusion Applications (PFMC), Aix en Provence, FRANCE, MAY, 2015International audienceA thermal wall model is developed for the SolEdge2D-EIRENE edge transport code for calculating the surface temperature of the actively-cooled vessel components in interaction with the plasma. This is a first step towards a self-consistent evaluation of the recycling of particles, which depends on the wall surface temperature. The proposed thermal model is built to match both steady-state temperature and time constant of actively-cooled plasma facing components. A benchmark between this model and the Finite Element Modelling code CAST3M is performed in the case of an ITER-like monoblock. An example of application is presented for a SolEdge2D-EIRENE simulation of a medium-power discharge in the WEST tokamak, showing the steady-state wall temperature distribution and the temperature cycling due to an imposed Edge Localised Mode-like event

Overview of progress in European medium sized tokamaks towards an integrated plasma-edge/wall solution

\u3cp\u3eIntegrating the plasma core performance with an edge and scrape-off layer (SOL) that leads to tolerable heat and particle loads on the wall is a major challenge. The new European medium size tokamak task force (EU-MST) coordinates research on ASDEX Upgrade (AUG), MAST and TCV. This multi-machine approach within EU-MST, covering a wide parameter range, is instrumental to progress in the field, as ITER and DEMO core/pedestal and SOL parameters are not achievable simultaneously in present day devices. A two prong approach is adopted. On the one hand, scenarios with tolerable transient heat and particle loads, including active edge localised mode (ELM) control are developed. On the other hand, divertor solutions including advanced magnetic configurations are studied. Considerable progress has been made on both approaches, in particular in the fields of: ELM control with resonant magnetic perturbations (RMP), small ELM regimes, detachment onset and control, as well as filamentary scrape-off-layer transport. For example full ELM suppression has now been achieved on AUG at low collisionality with n = 2 RMP maintaining good confinement . Advances have been made with respect to detachment onset and control. Studies in advanced divertor configurations (Snowflake, Super-X and X-point target divertor) shed new light on SOL physics. Cross field filamentary transport has been characterised in a wide parameter regime on AUG, MAST and TCV progressing the theoretical and experimental understanding crucial for predicting first wall loads in ITER and DEMO. Conditions in the SOL also play a crucial role for ELM stability and access to small ELM regimes.\u3c/p\u3