47 research outputs found
EXPERIMENTAL VALIDATION OF TILT-ROTOR AERODYNAMIC PREDICTIONS
No full textA comparison of experimental data with several numerical predictions of the aerodynamic loads on the
ERICA model is presented. The calculations are carried out by several Partners of the NICETRIP
consortium, with different codes, turbulence models and grids, with the objective of validating the
predictive capability of the CFD tools. Concerning the highly loaded minimum speed aircraft mode
AC1, a large separation on the wings has been shown, both by experimental measurements and CFD
simulations. Despite this large separation, a good agreement has been obtained between CFD
simulations and wind tunnel measurements. Strong aerodynamic interactions between the 4/rev.
blades passage and the tiltable wing, the nacelle and the fixed wing loads have been confirmed. Finally, we recommend increasing the aircraft speed flight and reducing the angle of attack for this configuration in order to avoid flow separation and reduce aircraft vibrations. In the highly loaded conversion mode CC4, a good agreement between CFD and experimental results has also been shown, in addition to 4/rev. loads fluctuations leading to aircraft vibrations
The Blind Test Activity of TILTAERO Project for the Numerical Aerodynamic Investigation of a Tiltrotor
No full textThe present paper illustrates an aerodynamic analysis performed by CIRA in the framework of the European research project TILTAERO (TILTrotor interactional AEROdynamics) by the application of a BEM methodology and with the aim to investigate the problem of the interactional aerodynamics of a tilt rotor configuration. Due to the lack of experimental database on tilt rotor configurations the one produced during the European research project PROPWING and referring to a propeller-nacelle-wing configuration has been chosen for the numerical-experimental comparison activity. The paper provides a synthetic description of the TILTAERO project and illustrates the main aspects of the PROPWING configuration and the relative experimental database. The main features of the numerical methodology applied is also described. The comparative study is performed by illustrating the numerical and experimental results in terms of steady, time-averaged and unsteady pressure distribution as well as steady and time-averaged normal forces acting on the wing. The results obtained indicate, in general, a satisfactory agreement of the methodology applied with the experiment
Code to Code Comparison of Aircraft-Mode Tilt-Rotor Aerodynamics
No full textA global comparison of several blind-test numerical predictions of the aerodynamic field around the
Erica model in aircraft mode, carried out by some Partners of the NICETRIP consortium, is presented.
The calculations are carried out with different codes, different turbulence models, different wind tunnel
setups and different grids, with the objective of supporting the future experimental test campaign in
the DNW-LLF and ONERA S1Ma wind tunnels. It is found that the level of unsteadiness introduced
by the rotor wake on the aerodynamic loads on the fuselage, wing and nacelle may be relevant. The
influence of the lower-mounted wind tunnel support is rather limited, while the rear-mounted support
introduces some local unsteady effects on the fuselage loads. The overall qualitative agreement of the
pressure distributions among different calculations is acceptable, while the scatter of the quantitative
average loads is somewhat important
TILT-ROTOR AERODYNAMICS ACTIVITIES DURING THE NICETRIP PROJECT
No full textThe aerodynamic re-design and characterization of the Erica tilt-rotor aircraft, carried out by some Partners of the NICETRIP consortium, is presented. The re-design activities concern some specific aircraft components, like the fuselage/wing fairing, the wing airfoils, the blade cuff and the rotor spinner. The aerodynamic characterization is carried out both experimentally and numerically, although
the present paper is focused on the numerical work, with the aim at identifying improvements of current ERICA geometry leading to improved aerodynamic performance
A Modular and Automated Annotation Platform for Handwritings: Evaluation on Under-Resourced Languages
No full textInternational audienceThere is today several approaches for automatic handwritten document analysis. HTR achieve in particular convincing results both in layout analysis and text recognition, but also in more up-to-date requests like name entity-recognition, script identification or manuscript datation. These systems are trained and evaluated with large open and specialized databases. Manual annotation and proofreading of handwritten documents is a key step to train such systems. However, it is a time-consuming task, especially when the formats required by the systems display considerable variations, or when the interfaces do not manage several level of information. We propose a new modular and collaborative interface online, ready-to-use, for multilevel annotation and quick-view solution for handwritten and printed documents, including for right-to-left languages. This interface undertakes the creation of customized projects, and the management, the conversion and the export of data in the different formats and standards of the state-of-the-art. It includes automated tasks for layout analysis and text lines extraction with high level fine-tuning capacities. We present this new interface through the case study of the creation of a database for Armenian, an under-resourced language with specific paleographical issues
