Improved Methods for the Assessment of the Generic Impact of Noise to the Environment 6th Framework Programme, Area 1.2.1, Policy-oriented research, contract number Propagation & meteorological effects Dirk Van Maercke IMAGINE Final Conference
IMAGINE Final Conference, Budapest, 25 October 2006 N° 2 Results of the HARMONOISE project P2P propagation models 2D + simple geometry Reference methods (PE, BEM, RAY) Engineering method (HarmonoiseP2P.DLL) Specific meteorological conditions Similarity theory + Monin-Obukhov lenght Input : wind speed, wind direction, cloudiness Experimental validation Road and railway Propagation up to 1 km Building on Harmonoise
IMAGINE Final Conference, Budapest, 25 October 2006 N° 3 WP1 : From 2D to 3D B uilding the 3D model (specifications & requirements) Construction of propagation paths in 2.5D WP4 : Aircraft sources H igher sources & greater propagation distances WP7 : Industrial sources Point sources & lateral diffraction Extended sources & location of equivalent point sources WP3 : Determination of L den and L night (long time averaging) Measurement or calculation (harmonised methodology) Based on statistics (conditions + frequency of occurrence) IMAGINE Building on Harmonoise…
IMAGINE Final Conference, Budapest, 25 October 2006 N° 4 Propagation paths in 2D Principles of the methods… 2.5D geometrical model Point-to-point
IMAGINE Final Conference, Budapest, 25 October 2006 N° 5 IMAGINE Outline of the harmonised models Source models Source segmentation Free field propagation Reflexions and lateral diffractions Air absorption Excess attenuation ground diffraction meteo
IMAGINE Final Conference, Budapest, 25 October 2006 N° 6 Measurements Reference model based on 3D ray-tracing Adaptation of the propagation model Lateral diffraction
IMAGINE Final Conference, Budapest, 25 October 2006 N° 7 Lateral diffraction Validation of ray-tracing by means of BEM-3D calculations
IMAGINE Final Conference, Budapest, 25 October 2006 N° 8 Lateral diffraction
IMAGINE Final Conference, Budapest, 25 October 2006 N° 9 Loss of coherency On input, source position: h S ± h S Turbulence and scattering (simplified, one parameter) Adaptation of the propagation model Size of the source & interference point sourceextended source
IMAGINE Final Conference, Budapest, 25 October 2006 N° 10 Engineering model : simplified solutions based on: Lateral diffraction Fresnel weighting Transition Diffracted ray paths S S
IMAGINE Final Conference, Budapest, 25 October 2006 N° 11 Adaptation of the propagation model High sources and long distance HARMONOISE AIRCRAFT LONG RANGE = unfavourable !
IMAGINE Final Conference, Budapest, 25 October 2006 N° 12 Extended domains of application GFPERay-Tracing Reference model = transition between GFPE and RAYS Engineering model = HARMONOISE + heuristic extensions
IMAGINE Final Conference, Budapest, 25 October 2006 N° 13 MODELLING PRINCIPLES: Linear sound speed gradient HARMONOISE : curved rays or curved ground analogy ? IMAGINE : conformal mapping ! Calculate the transformed profiles using c = constant. Adaptation of the propagation model Meteorological effects
IMAGINE Final Conference, Budapest, 25 October 2006 N° 14 Meteorological effects d = 500 md = 100 m d = 250 m NUMERICAL VALIDATION : GFPE h S = 0.30 m h R = 2.50m = 200 kNsm -4 A lin = 0.12 s -1
IMAGINE Final Conference, Budapest, 25 October 2006 N° 15 Validation & fine-tuning Excess attenuation versus equivalent linear gradient for a “point source”
IMAGINE Final Conference, Budapest, 25 October 2006 N° 16 Meteorological observations and equivalent linear gradient HARMONOISE validation = 120 calculations, all combinations of 8 wind directions, 3 wind speeds, 5 stability classes Surface observations :W, W, S Meteorological profiles : 1/L, U*, T* Lin/Log sound speed profile A = A T + A W cos ( SR - W ) B = B T + B W cos ( SR - W ) Linear sound speed profile 1/R = 1/R A + 1/R B Linear sound speed profile 1/R = 1/R A + 1/R B Measurement Propagation - direction - distance
IMAGINE Final Conference, Budapest, 25 October 2006 N° 17 Meteorological effects wind + thermal stability ISO , SRM2, NMPB
IMAGINE Final Conference, Budapest, 25 October 2006 N° 18 Meteorological effects and propagation classes One parameter: D/R 5 classes + frequency of occurrence
IMAGINE Final Conference, Budapest, 25 October 2006 N° 19 Determination of L den and L night Propagation classes
IMAGINE Final Conference, Budapest, 25 October 2006 N° 20 Determination of L den and L night Propagation classes Calculation and measurements: Calculation: Calculation of L den and L night requires (only) 4 calls to the P2P module, even less if p ij = 0 (short distances, high sources)
IMAGINE Final Conference, Budapest, 25 October 2006 N° 21 Determination of L den and L night Frequency of occurrence Meteorological Pre-processor Frequency of occurrence p ij Wind speed, Wind direction Cloud cover Day hours Evening hours Night hours Propagation distance Propagation direction Source / receiver height Meteorological data records
IMAGINE Final Conference, Budapest, 25 October 2006 N° 22 Propagation & meteorological effects More details & questions… this afternoon