EFFICIENT CALCULATION OF THE THREE-DIMENSIONAL SOUND PRESSURE FIELD AROUND A NOISE BARRIER

1996 ◽  
Vol 197 (5) ◽  
pp. 547-571 ◽  
Author(s):  
D Duhamel
Keyword(s):  
Sound Pressure ◽  
Pressure Field ◽  
Three Dimensional ◽  
Efficient Calculation ◽  
Noise Barrier

scholarly journals Modeling Study on the Asymmetry of Positive and Negative Storm Surges along the Southeastern Coast of China

2021 ◽  
Vol 9 (5) ◽  
pp. 458
Author(s):  
Dongdong Chu ◽  
Haibo Niu ◽  
Wenli Qiao ◽  
Xiaohui Jiao ◽  
Xilin Zhang ◽  
...  
Keyword(s):  
Storm Surge ◽  
Pressure Field ◽  
Three Dimensional ◽  
Storm Surges ◽  
Ocean Model ◽  
Central Pressure ◽  
Linear Interaction ◽  
Southeastern Coast ◽  
Zhoushan Archipelago ◽  
Wind Intensity

In this paper, a three-dimensional storm surge model was developed based on the Finite Volume Community Ocean Model (FVCOM) by the hindcasts of four typhoon-induced storm surges (Chan-hom, Mireille, Herb, and Winnie). After model validation, a series of sensitivity experiments were conducted to explore the effects of key parameters in the wind and pressure field (forward speed, radius of maximum wind (RMW), inflow angle, and central pressure), typhoon path, wind intensity, and topography on the storm surge and surge asymmetry between sea level rise (positive surge) and fall (negative surge) along the southeastern coast of China (SCC). The model results show that lower central pressure and larger RMW could lead to stronger surge asymmetry. A larger inflow angle results in a stronger surge asymmetry. In addition, the path of Chan-hom is the most dangerous path type for the Zhoushan Archipelago area, and that of Winnie follows next. The model results also indicate that the non-linear interaction between wind field and pressure field tends to weaken the peak surge elevation. The effect of topography on storm surges indicates that the peak surge elevation and its occurrence time, as well as the surge asymmetry, increase with a decreasing slope along the SCC.

scholarly journals Some Remarks Concerning Jones Eigenfrequencies and Jones Modes

2005 ◽  
Vol 12 (2) ◽  
pp. 337-348
Author(s):  
David Natroshvili ◽  
Guram Sadunishvili ◽  
Irine Sigua
Keyword(s):  
Exterior Domain ◽  
Thermal Stresses ◽  
Acoustic Pressure ◽  
Pressure Field ◽  
Three Dimensional ◽  
Boundary Surface ◽  
Isotropic Body ◽  
Oscillation Parameter ◽  
Uniqueness Of Solutions ◽  
Fluid Solid Interaction

Abstract Three-dimensional fluid-solid interaction problems with regard for thermal stresses are considered. An elastic structure is assumed to be a bounded homogeneous isotropic body occupying a domain , where the thermoelastic four dimensional field is defined, while in the unbounded exterior domain there is defined the scalar (acoustic pressure) field. These two fields satisfy the differential equations of steady state oscillations in the corresponding domains along with the transmission conditions of special type on the interface ∂Ω±. We show that uniqueness of solutions strongly depends on the geometry of the boundary ∂Ω±. In particular, we prove that for the corresponding homogeneous transmission problem for a ball there exist infinitely many exceptional values of the oscillation parameter (Jones eigenfrequencies). The corresponding eigenvectors (Jones modes) are written explicitly. On the other hand, we show that if the boundary surface ∂Ω± contains two flat, non-parallel sub-manifolds then there are no Jones eigenfrequencies for such domains.

Estimation of three-dimensional pressure field around a tire with wheelhouse by time-averaged PIV

2020 ◽  
Vol 2020 (0) ◽  
pp. OS03-14
Author(s):  
Katsuyuki YOKOYAMA ◽  
Shigeru MURATA ◽  
Hayato YOGOU ◽  
Yohsuke TANAKA
Keyword(s):  
Pressure Field ◽  
Three Dimensional

Simulation Investigation on Environment-Induced Pitting Corrosion on the Metal Surface

2021 ◽  
Vol 13 (5) ◽  
pp. 820-828
Author(s):  
Wei Zhang ◽  
Shengli Lv ◽  
Leijiang Yao ◽  
Xiaoyan Tong
Keyword(s):  
Mathematical Model ◽  
Pitting Corrosion ◽  
Three Dimensional ◽  
Corrosion Damage ◽  
Sudden Onset ◽  
Ion Concentration ◽  
Two Dimensional Image ◽  
Aging Aircraft ◽  
Efficient Calculation ◽  
The Mathematical Model

The prediction of corrosion damage is one of effective research methods in the safety inspection of aging aircraft structures. A mathematical model for quantifying corrosion damage is used in this paper to predict the onset of corrosion on structural surfaces exposed to aggressive environments. Based on the finite difference technique, the evolution process of local pitting corrosion on the surface of aluminum alloy in the medium is simulated, which can consider the sudden onset and the randomness of pitting corrosion. The effect of local ion concentration and oxide film damage on subsequent pitting nucleation was analyzed. Based on the efficient calculation program, the effectiveness of the mathematical model is verified by the comparison between the corrosion damage morphology and the experimental data in the literature. The results show a more widespread distribution of subsequent pits because of stronger aggressive ions are released during the life cycle of active pits and the higher diffusion coefficient of the aggressive ions. The three dimensional morphology is generated by image processing method based on the gray value of the two dimensional image of pits.

The Pressure Field Near a Ship Propeller

1958 ◽  
Vol 2 (01) ◽  
pp. 57-66
Author(s):  
John P. Breslin
Keyword(s):  
Sound Pressure ◽  
Pressure Field ◽  
Subsequent Paper ◽  
Naval Architecture ◽  
Fluctuating Pressure ◽  
Comparison With Experiment ◽  
Lifting Line ◽  
Ship Propeller

A brief summary is given of efforts in the field of naval architecture on the problem of determining the vibratory forces and moments produced by a ship propeller, and an account of the principal contributions made by aeronautical researchers on the problem of computing the fluctuating pressure field near a propeller. This pressure is derived from a lifting-line representation and the expressions are then interpreted in terms of the fields of two doublet distributions. It is shown that this result can be verified by specializing the expressions for the sound-pressure field of a propeller. Some characteristics of the pressure field are discussed briefly. Detailed evaluations and comparison with experiment will be presented in a subsequent paper.

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