技術情報とプレゼンテーション

The vibration of the walls of brass wind instruments has been a subject of study in the field of musical acoustics throughout the last decades. The amplitude of such vibrations, stimulated by the oscillating air pressure inside the instrument bore, is very small compared to the ... 詳細を見る

Otoacoustic emission (OAE) tests provide an objective examination of the cochlear function. However, the validity of OAE tests is affected negatively by calibration errors. This report sheds light on the evanescent waves arising at the interface between the OAE probe and the ear canal, ... 詳細を見る

The development of a quantitative nondestructive evaluation method, as an alternative to visual inspection, for inspecting pre-tensioned bolts in fracture critical bridges is presented. In order to understand the ultrasonic behavior of a wide variety of bolt geometries used in bridges, ... 詳細を見る

Acoustical well logging is an important technology for petroleum industry. Calibration and testing of tools in real wells is not feasible because the cost is high and the condition is not controllable. During manufacturing and maintaining, the logging tools are usually tested in a fluid ... 詳細を見る

This paper presents finite element method (FEM) simulation study of the generation of bulk acoustic waves (BAWs) and their effect on the performance of surface acoustic wave (SAW) devices, using COMSOL Multiphysics. A SAW delay line structure using YZ-cut lithium niobate substrate is ... 詳細を見る

The detection and identification of the location of a sound source is commonly done using arrays of microphones. A recent new alternative approach has been proposed which involves the use of continuous structures, such as beams or plates, as acoustic wave sensors. The sound wave ... 詳細を見る

The onshore wind turbine industry must overcome many technical, commercial, and environmental difficulties. A significant element for planning consent is operational noise. Acoustic limits are strictly enforced and can lead to near-neighbour complaints as well as contractual disputes. ... 詳細を見る

This work presents acoustic attenuation performance of helicoidal resonator due to distance change from different cross-sectional elements of cylindrical duct. The helicoidal resonator properties are described mainly in in infinite long cylindrical duct. For practical applications it is ... 詳細を見る

The Transfer Matrix method in the Acoustics Module of COMSOL Multiphysics is used when the whole system can be represented into a sequence of subsystems that interact only with adjacent subsystems. This method is frequently used in mathematics and, particularly, in acoustics. The ... 詳細を見る

We present a full modal -analysis of optical and acoustic properties based on two-dimensional finite-element method (2D-FEM) for Brillouin Gain spectrum (BGS) determination in optical fibers with COMSOL. This model enables us to predict precisely the BGS of any kind of silica fiber ... 詳細を見る