Italian Aerospace Research Centre

About: Italian Aerospace Research Centre is a other organization based out in Capua, Campania, Italy. It is known for research contribution in the topics: Aerodynamics & Morphing. The organization has 278 authors who have published 400 publications receiving 3563 citations. The organization is also known as: CIRA & Italian Aerospace Research Center.

Evaluating meteorological climate model inputs to improve coastal hydrodynamic studies

Abstract: . This work compares meteorological results from different regional climate model (RCM) implementations in the Mediterranean area, with a focus on the northern Adriatic Sea. The need to use these datasets as atmospheric forcings (wind and atmospheric pressure fields) for coastal hydrodynamic models to assess future changes in the coastal hydrodynamics, is the basis of the presented analysis. It would allow the assessment of uncertainties due to atmospheric forcings in providing coastal current, surge and wave climate changes from future implementations of hydrodynamic models. Two regional climate models, with different spatial resolutions, downscaled from two different global climate models (whose atmospheric components are, respectively, ECHAM4 and ECHAM5), were considered. In particular, the RCM delivered wind and atmospheric pressure fields were compared with measurements at four stations along the Italian Adriatic coast. The analyses were conducted using a past control period, 1960–1990, and the A1B IPCC future scenario (2070–2100). The chosen scenario corresponds to a world of very rapid economic and demographic growth that peaks in mid-century, with a rapid introduction of new efficient technologies, which balance fossil and non-fossil resources (IPCC, 2007). Consideration is given to the accuracy of each model at reproducing the basic statistics and the trends. The role of models' spatial resolution in reproducing global and local scale meteorological processes is also discussed. The Adriatic Sea climate is affected by the orography that produces a strengthening of north-eastern katabatic winds like bora. Therefore, spatial model resolution, both for orography and for a better resolution of coastline (Cavaleri et al., 2010), is one of the important factors in providing more realistic wind forcings for future hydrodynamic models implementations. However, also the characteristics in RCM setup and parameterization can explain differences between the datasets. The analysis from an ensemble of model implementation would provide more robust indications on climatic wind and atmospheric pressure variations. The scenario-control comparison shows a general increase in the mean atmospheric pressure values while a decrease in mean wind speed and in extreme wind events is seen, particularly for the datasets with higher spatial resolution.

Stability analysis of three-dimensional laminar compressible boundary layers based in ray-tracing theory and multiple scale technique

Abstract: The objective of the present work is to improve the physical understanding of specific 3D stability and transition processes in 3D mean flow by using a full stability theory, based on a multiple scales method and ray theory

A Contribution to Lifting Surfaces Aerodynamics Based on Time Domain Aeroacoustics

Abstract: Based on the Ffowcs Williams-Hawkings equation, a boundary integral method is presented for the calculation of the aerodynamic loading on thin lifting surfaces in linearized compressible flow. The final goal is providing aerodynamic inputs to aeroacoustic codes through the same procedure employed for determining the sound field. Several methods proposed over the last few years have been reviewed; then an aerodynamic formula has been chosen, which was derived by Milliken following an acoustic formulation proposed by Farassat. The method has been improved by adding some correcting terms, as a first step to turn the original lifting surface approach into an actual BEM formulation.

On the Use of Different Fundamental Solutions for the Interior Acoustic Problem

Abstract: An alternative form of fundamental solution to the Helmholtz equation is presented, which proves to be very effective when employed in the integral formulation for interior acoustic problems. A BEM code was developed based on this solution and gave satisfactory results in dealing with structural-acoustic coupling in a cavity, either with or without absorption walls. Theoretical arguments supporting the use of the alternative fundamental solution are provided; then the discussion of some numerical results highlights the main differences between the present method and the one using the well known free-space Green’s function as fundamental solution.

Periodic Patterns Recovery for Multicamera Calibration

Abstract: Camera calibration is an essential step for most computer vision applications. This task usually requires the consistent detection of a 2D periodic pattern across multiple views and in practice one of the main difficulties is a correct localization of the pattern origin and its orientation in case of partial occlusion. To overcome this problem many calibration tools require a full visibility of the calibration pattern, which is not always possible, especially when a multicamera systems are used. This paper addresses the specific problem of consistent recovery of the calibration pattern, captured by a multicamera systems under the condition of partial occlusion of the calibration object in several (even all) calibration images. The proposed algorithm is structured in two sequential steps aimed at the removal of the rotational and the translational components of the pattern offset transformation, which is essential for a correct calibration. The paper focuses on two common calibration patterns, the checkerboard grid and the bundle of parallel lines; however, the technique can be easily rearranged in order to cope with other classes of periodic patterns. The algorithm effectiveness has been successfully proven on the simulated data and two real calibration datasets, captured using a fisheye stereo rig.