Coupled flight dynamics and CFD - demonstration for helicopters in shipborne environment

The development of high-performance computing and computational fluid dynamics methods have evolved to the point where it is possible to simulate complete helicopter configurations with good accuracy. Computational fluid dynamics methods have also been applied to problems such as rotor/fuselage and main/tail rotor interactions, performance studies in hover and forward flight, rotor design, and so on. The GOAHEAD project is a good example of a coordinated effort to validate computational fluid dynamics for complex helicopter configurations. Nevertheless, current efforts are limited to steady flight and focus mainly on expanding the edges of the flight envelope. The present work tackles the problem of simulating manoeuvring flight in a computational fluid dynamics environment by integrating a moving grid method and the helicopter flight mechanics solver with computational fluid dynamics. After a discussion of previous works carried out on the subject and a description of the methods used, validation of the computational fluid dynamics for ship airwake flow and rotorcraft flight at low advance ratio are presented. Finally, the results obtained for manoeuvring flight cases are presented and discussed

Deep structure of the Ionian Sea and Sicily Dionysus - Cruise No. M111, October 10 - November 1, 2014, Catania (Italy) – Catania (Italy)

Summary The origin of the Ionian Sea lithosphere and the deep structure of its margins remain a little investigated part of the Mediterranean Sea. To shed light on the plate tectonic setting in this central part of southern Europe, R/V METEOR cruise M111 set out to acquire deep penetrating seismic data in the Ionian Sea. M111 formed the core of an amphibious investigation covering the Ionian Sea and island of Sicily. A total of 153 OBS/OBH deployments using French and German instruments were successfully carried out, in addition to 12 land stations installed on Sicily, which recorded the offshore air gun shots. The aim of this onshore-offshore study is to quantify the deep geometry and architecture of the Calabria subduction zone and Ionian Sea lithosphere and to shed light on the nature of the Ionian Sea crust (oceanic crust vs. thinned continental crust). Investigating the structure of the Ionian crust and lithospheric mantle will contribute to unravel the unknown ocean-continent transition and Tethys margin. Analyzing the tectonic activity and active deformation zones is essential for understanding the subduction processes that underlie the neotectonics of the Calabrian subduction zone and earthquake hazard of the Calabria/Sicily region, especially in the vicinity of local decoupling zones

Limits on the production of scalar leptoquarks from Z (0) decays at LEP

A search has been made for pairs and for single production of scalar leptoquarks of the first and second generations using a data sample of 392000 Z0 decays from the DELPHI detector at LEP 1. No signal was found and limits on the leptoquark mass, production cross section and branching ratio were set. A mass limit at 95% confidence level of 45.5 GeV/c2 was obtained for leptoquark pair production. The search for the production of a single leptoquark probed the mass region above this limit and its results exclude first and second generation leptoquarks D0 with masses below 65 GeV/c2 and 73 GeV/c2 respectively, at 95% confidence level, assuming that the D0lq Yukawa coupling alpha(lambda) is equal to the electromagnetic one. An upper limit is also given on the coupling alpha(lambda) as a function of the leptoquark mass m(D0)

Numerical Study of Rotors in Ship Airwake

No abstract available

Helicopter CFD Coupled with Flight Mechanics - Current Status and Future Perspectives

The development of High Performance Computing and CFD methods have evolved to the point where it is possible to simulate complete helicopter configurations with good accuracy. CFD methods have also been applied to problems such as rotor/fuselage and main/tail rotor interactions, performance studies in hover and forward flight, rotor design, etc. The GOAHEAD project is a good example of a coordinated effort to validate CFD for complex helicopter configurations. Nevertheless, current efforts are limited to steady flight and focus mainly on expanding the edges of the flight envelope. The present work tackles the problem of simulating manoeuvring flight in a CFD environment by integrating a multi-body grid motion method and the Helicopter Flight Mechanics (HFM) solver with CFD. After a discussion of previous works carried out on the subject and a description of the methods used, validation of CFD for ship airwake flow and rotorcraft flight at low advance ratio are presented. Finally, the results obtained for manoeuvring flight cases are presented and discussed

Helicopter CFD Coupled with Flight Mechanics - Current Status and Future Perspectives

The development of High Performance Computing and CFD methods have evolved to the point where it is possible to simulate complete helicopter configurations with good accuracy. CFD methods have also been applied to problems such as rotor/fuselage and main/tail rotor interactions, performance studies in hover and forward flight, rotor design, etc. The GOAHEAD project is a good example of a coordinated effort to validate CFD for complex helicopter configurations. Nevertheless, current efforts are limited to steady flight and focus mainly on expanding the edges of the flight envelope. The present work tackles the problem of simulating manoeuvring flight in a CFD environment by integrating a multi-body grid motion method and the Helicopter Flight Mechanics (HFM) solver with CFD. After a discussion of previous works carried out on the subject and a description of the methods used, validation of CFD for ship airwake flow and rotorcraft flight at low advance ratio are presented. Finally, the results obtained for manoeuvring flight cases are presented and discussed

The discrete spectrum of perturbed selfadjoint operators under non-signdefinite perturbations with a large coupling constant

Given two selfadjoint operators A and V=V_+-V_-, we study the motion of the eigenvalues of the operator A(t)=A-tV as t increases. Let #alpha#>0 and let #lambda# be a regular point for A. We consider the quantity N(#lambda#, A, W_+, W_-, #alpha#) defined as the difference between the number of the eigenvalues of A(t) that pass point #lambda# from the right to the left and the number of the eigenvalues passing #lambda# from the left to the right as t increases from 0 to #alpha#>0. We study asymptotic characteristics of N(#lambda#, A, W_+, W_-, #alpha#) as #alpha##->##infinity#. Applications to Schroedinger and Dirac operators are given. (orig.)SIGLEAvailable from TIB Hannover: RR 1596(387) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Numerical Study of Shipborne Rotors

No abstract available

Computational Fluid Dynamics Analyses of Ship Air Wakes Using Detached-Eddy Simulation

No abstract available