scholarly journals ABOUT THE APPROACHES TO MATHEMATICAL DESCRIPTION AND CALCULATION OF TIRE ROUAD NOISE RADIATION

Akustika ◽  
2019 ◽  
Vol 32 ◽  
pp. 97-99
Author(s):  
Andrey Vasilyev
Keyword(s):  
Mathematical Description ◽  
Sound Pressure ◽  
Environmental Temperature ◽  
Point Of View ◽  
Road Surface ◽  
Vehicle Engine ◽  
Movement Characteristics ◽  
Surface Climate ◽  
Vehicle Movement ◽  
Good Coincidence

Vehicles noise is a serious problem as from the point of view of impact to environment as due to the damage of vehicle's driver and passengers health. Usually in high vehicle's speed tires noise is the most significant noise source. Mathematical description of the process of sound generation from the moving source is described. Program provision for calculation of noise generation by the system "vehicle's tires – road surface" have been developed. Software is allowing to determine sound pressure level generated by vehicle's tires during vehicle movement taking to account the following factors: - velocity of vehicle movement; - characteristics of road surface; - climate characteristics (environmental temperature, rain, snow etc.); - construction characteristics of vehicle's tires; - dimensions and mass of vehicle; - engine capacity etc. Experimental data showed good coincidence with results of calculations by using of program provision.

scholarly journals RESEARCH INTO AUTOMOBILE MOVEMENT ON A CURVE UNDER WINTER CONDITIONS / AUTOMOBILIO JUDĖJIMO POSŪKYJE TYRIMAS ŽIEMOS SĄLYGOMIS

2012 ◽  
Vol 3 (6) ◽  
pp. 25-28
Author(s):  
Kristina Kemzūraitė ◽  
Šarūnas Mikaliūnas ◽  
Edgar Sokolovskij ◽  
Giedrius Garbinčius
Keyword(s):  
Road Surface ◽  
Lateral Acceleration ◽  
Winter Conditions ◽  
Vehicle Acceleration ◽  
Vehicle Movement

The article analyzes the movement of the car on the curve on the slippery and snowy road surface with asphalted ruts. The paper reviews literature related to lateral and longitudinal vehicle acceleration and dynamics of vehicle movement. The experimental facts of vehicle lateral acceleration are given in graphical charts. The article also describes the acceleration values and stability of the automobile depending on the speed in the curve. The findings are given based on the results. Santrauka Straipsnyje nagrinėjamas automobilio judėjimas posūkyje esant slidžiai ir snieguotai su asfaltuotomis provėžomis kelio dangai. Apžvelgiama literatūra, susijusi su automobilių skersiniais ir išilginiais pagreičiais, automobilių judėjimo dinamika. Eksperimentinėje dalyje pateikiami automobilių skersinių pagreičių grafikai. Nagrinėjamas pagreičių dydis ir automobilio stabilumas priklausomai nuo judėjimo greičio tame kelio posūkyje. Remiantis gautais rezultatais pateikiamos išvados.

Assessment of roadability and stability of a vehicle movement on the bend

2020 ◽  
Keyword(s):  
Mathematical Model ◽  
Road Surface ◽  
Inertia Force ◽  
Speed Limit ◽  
The Road ◽  
Inertial Moment ◽  
The Mathematical Model ◽  
Computer Imitation ◽  
Vehicle Movement

The paper presents the mathematical model and the technique of computer imitation of a vehicle movement on bend. Research of roadability and stability of the truck and the schedules illustrating change of characteristics of the steered movement have been obtained. The critical modes of the movement causing separation of wheels from road surface and side slippage have been defined. Speed limit of the steered movement on trajectory of the set curvature have been determined. Keywords vehicle, wheel, cross and longitudinal reactions of the road, inertia force, inertial moment, trajectory of a vehicle movement, angles of withdrawal of wheels, spring weight angle of heel, side slippage, vehicle drift

scholarly journals A Numerical Approach for Sound Quality of Vehicle Doors

2020 ◽  
Vol 25 (1) ◽  
pp. 9-16
Author(s):  
Erkut Yalçın ◽  
Halil Bilal ◽  
Ayhan Yağcı ◽  
Haluk Erol
Keyword(s):  
Sound Pressure ◽  
Sound Quality ◽  
Numerical Approach ◽  
Design Sensitivity ◽  
Point Of View ◽  
Vehicle Body ◽  
Fem Model ◽  
Body Development ◽  
Design Variables

A Vibro-Acoustic Finite Element Method (FEM) model capable of calculating the transient sound pressure generated by the door slam of a vehicle was developed in this study. A design sensitivity analysis (DSA) was performed for investigating the effects of major design variables on the related sound quality metrics. The methodology was developed using a sedan-car and its FEM model. This paper shows that a Computer Aided Engineering (CAE) model can be used as a rather powerful tool for giving design change decisions for the door components from sound quality point of view during vehicle body development according to psychoacoustic parameters.

Travelers’ exposure to vibrations and noise depending on the type of transport – the results of pilot research

2019 ◽  
Vol 570 (3) ◽  
pp. 23-27
Author(s):  
Magdalena Matys ◽  
Kamil Piotrowski ◽  
Dominik Mleczko ◽  
Paweł Pawlik
Keyword(s):  
Air Pollution ◽  
Time Domain ◽  
Public Transport ◽  
Sound Pressure ◽  
Heavy Traffic ◽  
Pressure Level ◽  
Point Of View ◽  
Vibration Acceleration ◽  
Passenger Cars ◽  
The Time Domain

For some time residents of big cities have been encouraged to change their means of transport, that is, to swap passenger cars for public transport vehicles. This is meant to help to reduce the problems associated with heavy traffic and air pollution. The authors of the article decided to check if such a change is also beneficial from the point of view of comfort and health of a person who uses public transport. For this purpose values of vibration acceleration and sound pressure level to which Cracow’s commuters are exposed to have been analyzed, depending on the type of vehicle they choose. In this respect measurements have been carried out for passenger cars, buses and trams. Two vehicle models of each type, significantly different from each other (old and new) have been selected for the tests. The measurements during a few trips in each type of vehicle on a predetermined route have been conducted. This article presents a comparison of measured values of vibroacoustic parameters in the time domain. It attempts to assess vibration and noise parameters, taking into account their impact on the health and comfort of the traveler.

scholarly journals Visual and acoustic performance of shading devices – real scale laboratory measurements

2019 ◽  
Vol 111 ◽  
pp. 06072 ◽  
Author(s):  
Tiberiu Catalina ◽  
Alexandra Ene ◽  
Andreea Biro
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Pressure Level ◽  
Point Of View ◽  
Physical Parameters ◽  
Main Role ◽  
Reverberation Time ◽  
Illuminance Level ◽  
Shading Devices ◽  
Enclosed Space

There are several physical parameters that are taken into consideration when determining the level of agreeability of an enclosed space. For instance, when choosing the louvers for a room there are a multitude of criteria that might be considered such as colour, material or the degree of opacity. However, these apparently small fixtures may have a significant impact also on other apparently unimportant factors like the sound pressure level and the reverberation time. This paper aims to present different types of devices used to control the way daylight enters a room, from both the illuminance level and the acoustical point of view. During the experimental campaign, five of the most common types of louvers were examined regarding their main role of blocking the light and moreover their influence on the reverberation time and sound pressure level in the analysed chamber.

Effect of environmental temperature on dietary selection in lactating sows

1991 ◽  
Vol 1991 ◽  
pp. 122-122 ◽  
Author(s):  
J M Vidal ◽  
S A Edwards ◽  
O MacPherson ◽  
P R English ◽  
A G Taylor
Keyword(s):  
Protein Intake ◽  
Environmental Temperature ◽  
Nutrient Content ◽  
Point Of View ◽  
Nutrient Requirements ◽  
Feeding Method ◽  
Temperature Changes ◽  
Lactating Sows ◽  
Summer Temperatures ◽  
Choice Feeding

The choice-feeding method has been suggested as an effective way of estimating nutritional requirements and it may be helpful from a practical point of view for meeting the nutrient requirements of animals with great variability in nutrient intake and requirements, for example sows in lactation. Friend (1971) reported high variability in protein intake in lactating sows on choice feeding. Growing rats (Leshner et al.,1971) respond to temperature changes by modifying the proportion of protein selected in order to maintain their protein intake. The main objective of this experiment was to investigate the ability of sows offered diets of different nutrient content to select the combination that best fits their requirement, particularly in relation to problems of reduced food intake routinely encountered in high summer temperatures.

A Comparison of Psychoacoustical Evaluation Methods for Vehicle Engine Noises Based on Wavelet Shrinkage Denoising Technique

2011 ◽  
Vol 219-220 ◽  
pp. 93-97 ◽  
Author(s):  
Yan Song Wang ◽  
Yue Yan ◽  
Zhi Qiu ◽  
Jin Zhang
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Quality Evaluation ◽  
Sound Quality ◽  
Pressure Level ◽  
Signal Denoising ◽  
Subjective Feeling ◽  
Wavelet Shrinkage ◽  
Vehicle Engine ◽  
Shrinkage Method

Based on the measured and denoised vehicle engine noises, the sound quality evaluation (SQE) techniques in common use for A-weighting sound pressure level (SPL) and psychoacoustical parameters, such as loudness, sharpness and roughness, are performed and compared in this paper. The wavelet threshold shrinkage method is adopted for sound signal denoising. The comparisons suggest that the A-weighting SPL is not sufficient and can only be used as a reference in vehicle SQE, the psychoacoustical parameters can provide a complete description and more exactly reflect to the subjective feeling of vehicle noises, should be considered in vehicle designs.

scholarly journals Selected Problems of Transport in Port Towns – Tri-City as an Example

2017 ◽  
Vol 24 (s1) ◽  
pp. 16-24 ◽  
Author(s):  
Marcin Budzyński ◽  
Dawid Ryś ◽  
Wojciech Kustra
Keyword(s):  
Traffic Safety ◽  
Road Traffic ◽  
Point Of View ◽  
Road Surface ◽  
Air Transport ◽  
Transport Systems ◽  
Sea Transport ◽  
The Road ◽  
Road Traffic Safety ◽  
Transport Problems

Abstract Port towns are strategic places from the point of view of transport systems. They form integration junctions for various transport branches , apart from the traditional - road and railway ones , also for water( sea) transport which is active there. Moreover, air transport comes also into consideration , whose efficient functioning must be connected with good accessibility, that concerns sea transport as well. Efficient and safe servicing the ports is crucial for their functioning. Problems associated with the overloading of lorries, which leads to degradation of road surface structure , observed in Gdynia, are discussed as an example in this paper. Problems of road traffic safety (RTS) are presented in this paper on the example of Gdańsk. The two issues: the road traffic safety and road surface degradation constitute only some transport problems of port towns , but they are very important, from the point of view of their specificity, for integration junctions of all the transport branches for people and goods. However, in discussing selected aspects of transport in port towns it is necessary to refer to the managing of integrated transport system with taking into account its traffic safety aspects.

scholarly journals The experience of applying mathematical methods for analysis of the microgeneration sector in Russia

2021 ◽  
pp. 153-160
Author(s):  
Gavriusev Vladimirovich ◽  
Maxim Vasilyevich-Chernyaev
Keyword(s):  
Gaussian Mixture Model ◽  
Feasibility Study ◽  
Economic Efficiency ◽  
Mathematical Description ◽  
Quantitative Methods ◽  
High Efficiency ◽  
Gaussian Mixture ◽  
Economic Feasibility ◽  
Point Of View ◽  
Mathematical Methods

The paper relates to substantiation of reasonability of applying the mathematical methods to economic researches. The developed by the author algorithm for determining the relevant for Russia foreign experience of the microgeneration sector development on the basis of the Gaussian mixture model is provided as an example. This algorithm used to be successfully applied within the framework of a larger scale research related to the problems of development and increasing of the economic efficiency of the microgeneration sector in Russia. The paper provides for the mathematical description and economic feasibility study of the measures taken. High efficiency of using the quantitative methods for obtaining the results, which are significant from the point of view of the economic feasibility study, is underlined. There are also described the problematic issues of the suggested algorithm and possible ways of solving thereof. Finally, the conclusion is made about a high heuristic value of the above-described algorithm and the reasonability of applying the mathematical methods to economic researches.

scholarly journals Investigation of Vehicle Stability with Consideration of Suspension Performance

2021 ◽  
Vol 11 (20) ◽  
pp. 9778
Author(s):  
Vaidas Lukoševičius ◽  
Rolandas Makaras ◽  
Arūnas Rutka ◽  
Robertas Keršys ◽  
Andrius Dargužis ◽  
...  
Keyword(s):  
Road Surface ◽  
Vehicle Body ◽  
Vehicle Suspension ◽  
Original Structure ◽  
Vehicle Stability ◽  
Main Task ◽  
The Road ◽  
Movement Stability ◽  
On The Road ◽  
Vehicle Movement

The issue of movement stability remains highly relevant considering increasing vehicle speeds. The evaluation of vehicle stability parameters and the modeling of specific movement modes is a complex task, as no universal evaluation criteria have been established. The main task in modeling car stability is an integrated assessment of the vehicle’s road interactions and identification of relationships. The main system affecting the vehicle’s road interaction is the suspension of the vehicle. Vehicle suspension is required to provide constant wheel to road surface contact, thus creating the preconditions for stability of vehicle movement. At the same time, it must provide the maximum possible body insulation against the effect of unevennesses on the road surface. Combining the two marginal prerequisites is challenging, and the issue has not been definitively solved to this day. Inaccurate alignment of the suspension and damping characteristics of the vehicle suspension impairs the stability of the vehicle, and passengers feel discomfort due to increased vibrations of the vehicle body. As a result, the driving speed is artificially restricted, the durability of the vehicle body is reduced, and the transported cargo is affected. In the study, analytical computational and experimental research methods were used. Specialized vehicle-road interaction assessment programs were developed for theoretical investigation. The methodology developed for assessing vehicle movement stability may be used for the following purposes: design and improvement of vehicle suspension and other mechanisms that determine vehicle stability; analysis of road spans assigned with characteristic vehicle movement settings; road accident situation analysis; design of road structures and establishment of certain operational restrictions on the road structures. A vehicle suspension test bench that included original structure mechanisms that simulate the effect of the road surface was designed and manufactured to test the results of theoretical calculations describing the work of the vehicle suspension and to study various suspension parameters. Experimental investigations were carried out by examining the vibrations of vehicle suspension elements caused by unevenness on the road surface.

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