Over the last few years, customer demands regarding acoustic performance, along with the tightening of legal regulations on noise emission levels and human exposure to noise, have made the noise and vibration properties into important design criteria for agricultural machinery cabins. In this framework, both experimental analysis procedures for prototype testing as well as reliable numerical pr...

The high level of noise in helicopter cabins considerably compromises the comfort and safety pilot passengers. To verify feasibility effectiveness microperforated panel composite sound absorption structures for suppression cabins, simulation experimental studies were conducted on a model light cabin. First, three cabin wall designed. Then, finite element main gear/body acoustic vibration coupli...

in this paper the interior noise level of a vehicle due to structural vibration, named structure borne noise, as a part of nvh analysis has been investigated. first structural analysis is performed and vibrational behavior of structure carried out due to power plant excitations. then interior acoustic cavity response for such excitation and resultant noise is determined. vibrational analysis is...

A Cabin Car Communication System (CCCS) has the goal of improving the communication among passengers inside the car. Wind, road and engine noise, the distance between passengers and other factors make difficult the communication inside vehicles. The driver must often look away from the road and passengers move out of normal seating positions. The CCCS makes use of a set of microphones to pick u...

Apreconditioner defined by an algebraicmultigrid cycle for a dampedHelmholtz operator is proposed for the Helmholtz equation. This approach is wellsuited for acoustic scattering problems in complicated computational domains and with varying material properties. The spectral properties of the preconditioned systems and the convergence of the GMRESmethod are studiedwith linear, quadratic, and cub...

In recent years, need to increase the convenience of trips in railway vehicles causes that train operators and manufacturers focus on reducing the noise level which is sensed by passengers. In this paper, first the state of modeling acoustic noise in cab train is discussed and natural frequencies and acoustic mode shapes are derived and then formulation of acoustic pressure in the cab will be o...

The low frequency interior noise in cars is for a large part the result of structure borne excitation. The transfer of the structure borne sound involves a large number of components of the engine suspension, wheel suspension and chassis which are all potentially contributing to the overall noise level. This process can be analyzed through acombination of transfer function measurementswith oper...

One of the aims of the EU project FACE (Friendly Aircraft Cabin Environment) is to reduce aircraft interior noise. For modern aircraft flying at cruise conditions, the turbulent boundary layer is the main source for cabin noise. Normally, the turbulent boundary layer causes the trim panels to vibrate, and hence to radiate sound into the aircraft cabin. The purpose of the present work is to redu...

The need to hear, comprehend and be able to recall spoken information can exist in less than ideal listening conditions. Such a situation occurs within an aircraft cabin where, despite improvements in modern passenger aircraft, the acoustic properties of the cabin are less than ideal for understanding speech. It is important that passengers, who are untrained and or new to the environment, hear...

thermal modeling of an automotive cabin was performed in this paper to predict the inside cabin air temperature. to implement this task, thermal and ventilation loads were estimated and the mass and energy balance conservation equations for dry air and water vapor with considering a new parameter (air circulation ratio) as well as the balance equations of internal components of a cabin were der...