Side Window Glass Research Articles

Design of full vehicle PBNR based on side windows with embedded acoustic black holes

Acoustic black holes (ABH) have been proven to be a lightweight structure with wide application prospects in wave tuning, energy recovery, and vibration and noise reduction. The side window glass is one of the important noise propagating paths into vehicle interior. In this paper, a new side window glass based on ABHs is designed and the influence of the new side window glass on the full vehicle PBNR is analyzed. A full vehicle SEA model is established and verified using the PBNR test. The transmission paths contributing the most noise energy to the driver's head cavity under excitations at different positions are analyzed. The results show that the side window glass is the main weak component needed to be optimized in the analysis frequency band. The influence of the new type of side window glass on the whole vehicle PBNR is studied based on the full vehicle SEA model. It is observed that by comparing with the traditional glass, the new glass can significantly improve the PBNR at the coincidence frequency of glass under different paths and meanwhile reduce the weight of the glass. It can provide a new technology for improving vehicle interior noise control.

Sound insulation design of vehicle side window glass based on acoustic black holes

Acoustic black holes (ABHs) can reduce the mechanical vibration and radiated sound of a structure while simultaneously reducing its mass. By considering the practical application, a new vehicle side window glass is designed using ABH array to optimize its sound insulation performance in this paper. The finite element method (FEM) is used to analyze the response and modes of the glass to validate its ABH effect. The accuracy of the Finite Element-Stational Energy Analysis (FE-SEA) model is verified using Gaussian expansion method (GEM) and Statistical modal Energy distribution Analysis (SmEdA). Using the verified FE-SEA, the transmission loss (TL) of the new side window glass and the influence of the number of ABH layers are analyzed. It is observed that the overall TL of the new glass is better than that of the traditional one, which can highly improve the TL at the coincidence frequency and meanwhile reduce the weight. It provides a new technique to design vehicle glass to improve vehicle sound insulation performance.

Application of Acoustic-solid Coupling Theory in New Energy Vehicle Noise Control

The development of new energy vehicles has attracted much attention due to the strong promotion and popularisation of the concept of low carbon and environmental protection, and the increasing demand for environmental protection in cars. Although these vehicles meet people’s requirements for resource and environmental protection, the noise generated during the driving process affects the comfort of the vehicle occupants and the concentration of the vehicle driver. To address this problem, the research proposes to improve the noise control technology of new energy vehicles based on acoustic-solid coupling theory and to test the practical application effect of this technology. The test results show that the maximum acceleration of vibration at the roof, floor, axle head, and spring of the new energy vehicle are 1.48 m/s2, 1.02 m/s2, 0.079 m/s2, and 0.020 m/s2 respectively, which are lower than the maximum acceleration before the use of this technology. The maximum sound pressure at the windscreen and side window glass of the new energy vehicle is 80 dB(A) and 73 dB(A) after the use of this technology. The maximum sound pressure at the driver’s ear was 62 dB(A) and 77 dB(A) when the vehicle was driven on different road surfaces, which were lower than the sound pressure values before use. In summary, the research proposes to improve the noise control technology of new energy vehicles based on the sound-solid coupling theory, which can have the effect of reducing the noise value generated by new energy vehicles and improving the comfort of users.

Strength and durability characteristics of concretes with crushed side window glass as partial aggregate substitution

Strength and durability characteristics of concretes with crushed side window glass as partial aggregate substitution

Optimization study on the influence of rearview mirror and side window glass on interior noise

Based on the LES model, the compressible transient CFD simulation combined with the acoustic finite element method optimizes the effect of the rearview mirror and side window glass on in-vehicle noise from the perspective of sound source and transmission. The primary and secondary orders of the influence of different mirror shape and side window glass geometric parameters on the noise in the car were obtained through the design and analysis of orthogonal experiments, and the results of the flow and sound fields were compared. The following results are presented: acoustic source noise reduction from the rearview mirror is mainly affected by acoustic pressure excitation. The proportion of the mirror body of the rearview mirror, the angle of the lower edge, and the length of the mirror column affect the noise in the car in turn. The noise reduction control with PVB laminated glass as the transmission path is mainly limited by the low frequency turbulent pressure excitation. The inner and outer thicknesses of PVB laminated glass have different influences on the noise in the car under different frequency bands, and the results in the full frequency band are mainly affected by the low frequency band.

Computational fluid dynamics simulation and performance optimization of an electrical vehicle Air-conditioning system

In vehicles, air conditioning tends to offer efficient thermal conditioning and air circulation inside cabin for passenger comfort from different climate variation. The working performance of air conditioning system in vehicles is an essential factor for thermal comfort and driving safety of the passenger compartment of vehicles. Therefore, it is of great significance to construct a numerical simulation model for theoretical analysis and performance evaluation of vehicle air conditioning system. In current research, the air conditioning system of an electric vehicle is taken as the research subject. Internal flow field characteristics of air conditioning system is investigated by Computational Fluid Dynamics (CFD). Results show that the air flow in air-conditioning system is relatively smooth, and the velocity distribution in the front windshield A area and the driver's field of vision of the left and right windows is not ideal when the defrosting-demisting mode is on; the velocity and air quantity distribution of the two outlets in the middle air duct are not uniform under blowing mode. In view of the uneven distribution of velocity and air quantity, the corresponding optimization scheme is proposed. After optimization, the cell relative velocity of the front windshield is significantly improved, and velocity distribution of the side window glass is slightly increased and the defrosting-demisting performance meets the vehicle defrosting requirements of national standard; after optimization, the air quantity distribution of the air ducts at blowing mode is more uniform, which is conducive to the comfort of the passenger compartment.

Flow-induced vibration analysis of a vehicle's front side window glass

This study analyses the flow-induced vibration of a car's front side window glass. The following working steps were carried out: experimental modal analysis to yield the dynamic characteristics of the system; wind tunnel experiments and corresponding numerical simulations with a computational fluid dynamics (CFD) code to acquire the pressure field including the fluctuations on the side glass; and a MATLAB implementation of the vibration velocity response calculated with the Corcos model and Mellen elliptical model. The MATLAB model calculates the averaged vibration velocity response by means of the pressure loading from the wind tunnel test or from the CFD simulations as well as by means of the result of the experimental modal analysis. The hereby calculated vibration response of the side glass has been validated by the results of laser Doppler vibrometer measurements in the wind tunnel. Through parameter study with the MATLAB algorithm, it was found that flow convective velocity with U c = 0.6*U, flow decay rates with α x = 0.1 and α z = 0.77 could be considered as the suitable values for the structure vibration velocity response calculation in this type of flow with a low Mach number.

Sound Radiation Analysis of a Front Side Window Glass of DrivAer Model under Wind Excitation

To study the car radiated noise caused by turbulent pressure fluctuation on the side glass under wind excitation, a clay model of DrivAer was constructed except that the front left side window was built with real glass. Firstly, the constraint boundary condition of the side glass was set equivalent to a series of springs for the modelling with Finite Element Method (FEM). Then, a platform based on Matlab‐Abaqus cosimulation was originally developed, and the genetic algorithm was applied to find out the best fitted spring stiffness, which was used to build the equivalent model. Then working as excitation, the Corcos model was applied to calculate the power spectrum density of the turbulence pressure fluctuations acting on the side glass. Subsequently, the finite element modal superposition method was used to solve the vibroacoustic coupling equation to get the noise level of the driver’s ear position in the vehicle interior. Finally, the surface vibration velocity distribution of side glass under wind excitation was measured with Laser Vibrometer and then with Boundary Element Method (BEM), the radiated noise into interior was calculated as well (semisimulation). Through comparison of these two results, it shows good agreement up to 1000 Hz. It demonstrates that the above method is applicable to calculate the sound radiation caused by the side glass’ vibration at the low and middle frequency range. Therefore, an approach of calculating sound radiation of a vibrating glass caused by the air convective pressure fluctuation was explored.

Discrimination of side-window glass of Korean autos by laser ablation inductively coupled plasma mass spectrometry.

Fragments of glass from cars are often found at crime scenes and can be crucial evidence for solving the crime. The glass fragments are important as trace evidence at crime scenes related to car accidents and burgled homes. By identifying the origin of glass fragments, it is possible to infer the identity of a suspect. Our results represent a promising approach to a thorough forensic investigation of car glass. Thirty-five samples from the side windows of cars produced and used in South Korea were collected from the official agencies of five car manufacturers and from two glassmakers. In addition, 120 samples from side mirrors were collected from the same suppliers as well as from small businesses. Their chemical compositions (including Pb isotopes) were analyzed using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and linear discriminant analysis (LDA) was performed. The percentages of major elements (Si, Ca, and Fe) in side-window glass varied within narrow ranges (30.0±2.36%, 5.93±0.52%, and 0.33±0.05%, respectively), while the differences among Pb isotope ratios were not significant. In contrast, light rare earth elements (LREEs) were different from each glassmaker. From the LDA, the types of side-window glass were successfully discriminated according to car manufacturer, glassmaker, and even glass thickness. However, glass from side mirrors cannot be used for good forensic identifiers. Discrimination techniques for side-window glass, although not for side mirrors, using chemical compositions combined with multivariate statistical analyses provide evidence for forensic investigations. Copyright © 2016 John Wiley & Sons, Ltd.

Verification of Automobile Aerodynamic Noise Transmitted through Side Window Glass

Verification of Automobile Aerodynamic Noise Transmitted through Side Window Glass

Laminated Safety Glass as an Intermediate Target: A Wound Ballistic Study

Various 9-mm ammunitions (A1, A4, A5, ST, GS, GSb, P.E.P., SeCa, HP, PTP/s, VM, McVG, DM41, PTP, SX2, PT, and MEN frangible) were tested regarding their velocity, energy, angle of impact, and potential wound channel after penetrating a car window at 30° and 90°. Test materials were gelatine, soap, and pig cadavers. The velocities of the projectiles were between c. 288 and 430 m/ses, the energy spread between 394 and 564 J. Handgun bullets fired through vehicular side window glass lose substantial energy reducing the effectiveness of the ammunition. This effect is greater when fired at an angle of 30° compared to 90°. At a shooting angle of 90°, none of the different projectiles showed remarkable differences considering its wound ballistic features. Accuracy is maintained at a 90° angle but seriously impaired at 30°. None of the examined ammunition complied with the demanded wound channel effectiveness of 30-60 J/cm.

Influence of Crosswind to Automobile Interior Aerodynamic Noise

After a brief introduction about aerodynamic noise generation and transmission mechanisms, the influence of crosswind to vehicle interior aerodynamic noise for a production automobile sedan was investigated through full-scale aeroacoustic wind tunnel tests. Through analysis of sound pressure level of vehicle interior driver ear position and pressure fluctuation level on vehicle side window glass under different yaw angles, the following results are obtained: The frequency characteristics of vehicle interior aerodynamic noise vary as yaw angle changes under one certain wind speed. Whether on the leeside or by windward, sound pressure level increases as yaw angle goes up. Under the same yaw angle, interior noise level on the leeside is higher than that by windward. Test results between pressure fluctuation level on side window glass and vehicle interior aerodynamic noise of driver ear position show good correlation

Is Differentiation of Frequently Encountered Foreign Bodies in Corpses Possible by Hounsfield Density Measurement?

The radiological determination of foreign objects in corpses can be difficult if they are fragmented or deformed. With multislice computed tomography, radiodensities--referred to as Hounsfield units (HU)--can be measured. We examined the possibility of differentiating 21 frequently occurring foreign bodies, such as metals, rocks, and different manmade materials by virtue of their HU values. Gold, steel, and brass showed mean HU values of 30671-30710 (upper measurable limit), mean HU values for steel, silver, copper, and limestone were 20346, 16949, 14033, and 2765, respectively. The group consisting of objects, such as aluminum, tarmac, car front-window glass, and other rocks, displayed mean HU values of 2329-2131 HU. The mean HU value of bottle glass and car side-window glass was 2088, whereas windowpane glass was 493. HU value determination may therefore help in preautopsy differentiation between case-relevant and irrelevant foreign bodies and thus be useful for autopsy planning and extraction of the objects in question.

Predictors of traumatic rupture of the aorta in near-side impacts

Individual non-minor injuries (Abbreviated Injury Scale (AIS)≥ 2) to the head that occurred to belted and unbelted drivers and front seat passengers on the struck side of impacted vehicles were examined. Injury type, injury combination, collision severity in relation to type of injury as well as contact sources were assessed. Forty-eight percent of injuries were moderate in severity (AIS 2). The most common type of injury was the diffuse brain injury, typically marked by a short period of unconsciousness, which occurred in collisions of lower severity than focal brain and skull fracture injuries. One-hundred and five out of 216 (48.6%) of contact sources for all injury types originated from outside the vehicle and such exterior sources were more likely to result in high severity injuries. Thirty percent of injuries resulted from head contacts with other vehicles. The most frequent vehicle interior contact source was the side window glass. Diffuse injuries tended to occur independently of other injury types and were more likely to originate from an interior rather than exterior contact. Preventative measures for head injury reduction in lateral collisions are discussed. Overall, the data show that proposed and present European and U.S. lateral impact test methods do not address many head injury problems such as those included in this study.

Implication for photosensitive patients of ultraviolet A exposure in vehicles

Photosensitive patients sometimes report disease flares during journeys by car. Window glass blocks all UVB but not all UVA. All car windscreens are made from laminated glass. Side and rear windows are usually made of nonlaminated glass. To determine which types of glass provide most protection from UVA with particular reference to the implications for patients with polymorphic light eruption (PLE). The percentage transmission of UVA was determined for a selection of glass, both laminated and nonlaminated, and with differing colour tints. Laminated glass transmits less UVA than nonlaminated glass. Tinted glass transmits less UVA than clear glass. Nonlaminated clear glass transmitted the highest percentage of UVA (62.8%) and grey laminated glass the lowest (0.9%). A dose of 5 J cm(-2) UVA, enough to trigger PLE in some patients, could be transmitted through clear nonlaminated glass in 30 min but would take 50 h through grey laminated glass. Patients with severe UVA-induced PLE and other photosensitivity disorders may have disease flares from solar UVA transmission through side-window glass. Protective measures such as wearing long-sleeved clothing, keeping the arm beneath the bottom of the window aperture, or choosing tinted and laminated car windows may be helpful.

97/05033 Thermal comfort analysis inside a car: Chakroun, W. and Al-Fahed, S. Int. J. Energy Res., 1997, 21, (4), 327–340

In vehicles, air conditioning tends to offer efficient thermal conditioning and air circulation inside cabin for passenger comfort from different climate variation. The working performance of air conditioning system in vehicles is an essential factor for thermal comfort and driving safety of the passenger compartment of vehicles. Therefore, it is of great significance to construct a numerical simulation model for theoretical analysis and performance evaluation of vehicle air conditioning system. In current research, the air conditioning system of an electric vehicle is taken as the research subject. Internal flow field characteristics of air conditioning system is investigated by Computational Fluid Dynamics (CFD). Results show that the air flow in air-conditioning system is relatively smooth, and the velocity distribution in the front windshield A area and the driver's field of vision of the left and right windows is not ideal when the defrosting-demisting mode is on; the velocity and air quantity distribution of the two outlets in the middle air duct are not uniform under blowing mode. In view of the uneven distribution of velocity and air quantity, the corresponding optimization scheme is proposed. After optimization, the cell relative velocity of the front windshield is significantly improved, and velocity distribution of the side window glass is slightly increased and the defrosting-demisting performance meets the vehicle defrosting requirements of national standard; after optimization, the air quantity distribution of the air ducts at blowing mode is more uniform, which is conducive to the comfort of the passenger compartment.

Head injuries in lateral impact collisions

Individual non-minor injuries (Abbreviated Injury Scale (AIS)≥ 2) to the head that occurred to belted and unbelted drivers and front seat passengers on the struck side of impacted vehicles were examined. Injury type, injury combination, collision severity in relation to type of injury as well as contact sources were assessed. Forty-eight percent of injuries were moderate in severity (AIS 2). The most common type of injury was the diffuse brain injury, typically marked by a short period of unconsciousness, which occurred in collisions of lower severity than focal brain and skull fracture injuries. One-hundred and five out of 216 (48.6%) of contact sources for all injury types originated from outside the vehicle and such exterior sources were more likely to result in high severity injuries. Thirty percent of injuries resulted from head contacts with other vehicles. The most frequent vehicle interior contact source was the side window glass. Diffuse injuries tended to occur independently of other injury types and were more likely to originate from an interior rather than exterior contact. Preventative measures for head injury reduction in lateral collisions are discussed. Overall, the data show that proposed and present European and U.S. lateral impact test methods do not address many head injury problems such as those included in this study.