Results 81 to 90 of about 10,609 (238)

Stratospheric and tropospheric seasonality and its implications for observation requirements in numerical weather prediction

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Daily time series of zonal‐mean zonal wind (m·s−1) at 10 hPa and 60° N from 1950 to 2021 from the ERA5 reanalysis. This shows huge variability in some seasons and very little in others. We provide evidence that high‐level observations, radiosonde and satellite, are more important during the extended winter season with its very large variability ...
Bruce Ingleby, Inna Polichtchouk
wiley   +1 more source

Exploiting Aeolus winds in a regional numerical weather prediction model

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Aeolus measured winds have proven to be beneficial for global models. However, demonstrating positive impact for limited‐area models has been a challenge so far. For the first time, we have demonstrated a statistically significant positive impact of Aeolus winds in a limited‐area model by using the 4DVar data assimilation technique and the most recent ...
Gert‐Jan Marseille, Roohollah Azad, Martin Ridal, Susanna Hagelin   +3 more
wiley   +1 more source

The benefits of a hybrid‐3DEnVar data assimilation scheme for the convection‐permitting NWP model AROME–Austria

Quarterly Journal of the Royal Meteorological Society, EarlyView.
The climatological‐error covariance matrix used in three‐dimensional variational data assimilation (3DVar) provides smooth and isotropic increments spread to long distances. In contrast, three‐dimensional ensemble variational data assimilation (3DEnVar) with a purely ensemble‐error covariance matrix provides inhomogeneous increments and contains the ...
Kaushambi Jyoti, Philipp Griewank, Florian Meier, Martin Weissmann   +3 more
wiley   +1 more source

Numerical simulation and physical understanding of a locally initiated sea fog event over the eastern Yellow Sea with a transition of air–sea temperature difference

Quarterly Journal of the Royal Meteorological Society, EarlyView.
Unexpected sea fog in the west coast of South Korea had a huge impact on the transportations in the Seoul–Incheon metropolitan area. We reproduced successfully the formation and evolution of a sea event with a transition of air–sea temperature difference using the Weather Research and Forecasting model.
Jeonghoe Kim, Jung‐Hoon Kim, Clive E. Dorman, Harindra J. S. Fernando   +3 more
wiley   +1 more source

Evaluation of the influence of the number of blades and diameter on propeller noise

Вестник Самарского университета: Аэрокосмическая техника, технологии и машиностроение, 2016
The article presents the results of computational and experimental research of the effect of the number of blades and the diameter on the noise of the propeller operating at Reynolds numbers of more than 106. It is shown that an increase in the number of
P. A. Moshkov, V. F. Samokhin
doaj   +1 more source

Sliding Mode Control in Aerospace Applications: A Survey

International Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT Sliding mode control (SMC) enjoys robustness to matched and unmatched (in the case of minimum phase input‐output dynamics) bounded perturbations, and finite time convergence. Second‐order and higher‐order sliding mode control systems (2‐SMC/HOSMC) retain all the advantages of sliding mode control, but in addition can be applied to systems of ...
Yuri Shtessel, Christopher Edwards
wiley   +1 more source

Deep Reinforcement Learning‐Based Control for Real‐Time Hybrid Simulation of Civil Structures

International Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT Real‐time Hybrid Simulation (RTHS) is a cyber‐physical technique that studies the dynamic behavior of a system by combining physical and numerical components that are coupled through a boundary condition enforcer. In structural engineering, the numerical components are subjected to environmental loads that become dynamic displacements of the ...
Andrés Felipe Niño, Alejandro Palacio‐Betancur, Piedad Miranda‐Chiquito, Juan David Amaya, Christian E. Silva, Mariantonieta Gutierrez Soto, Luis Felipe Giraldo   +6 more
wiley   +1 more source

Validation of a Particle Image Velocimetry Algorithm Through Comparative Field and Laboratory Analysis

River Research and Applications, EarlyView.
ABSTRACT Flow velocity measurement is fundamental to hydrological and hydraulic studies, providing essential data for streamflow estimation and river dynamics analysis. Traditional in situ methods like propeller gauges and acoustic Doppler current profilers are accurate but intrusive and labour‐intensive, while non‐intrusive image processing methods ...
Ghazaleh Nassaji Matin, Gareth Bradbury, Alan Puttock, Kirsty Frith, Diego Panici   +4 more
wiley   +1 more source

Aircraft Noise Assessment Using Noise Points: Conception and Verification

Aerospace
The increase in global air traffic volumes has significant economic and ecological impacts. A key factor in this context is the development of the noise situation around airports.
Jason Blinstrub, Rainer Schmid
doaj   +1 more source

Acoustic analysis of chevron nozzle: A CFD approach [PDF]

E3S Web of Conferences
Noise pollution from aircraft is a critical environmental issue, affecting not only wildlife but also human health and comfort, especially for populations living near airports.
Alsalami Zaid, Sharma Sanjeev, Jeevan Nagendra Kuma Y., Kansal Lavish, Singh Shivani, Vishkarma Manoj Kumar   +5 more
doaj   +1 more source