Cabin Interior Research Articles

Concentrations and Source Apportionment of Tetrachloroethylene (PCE) in Aircraft Cabins

The aircraft cabin provides a unique indoor environment compared to other building environments. Tetrachloroethylene (PCE) is widely found in cabins and has clear adverse health impacts. This study investigated the PCE pollution characteristics in 56 aircraft cabins using on-flight Tenax-TA tube sampling and GC-MS analysis. PCE was detected at a high rate of 79% in sampled flights, indicating widespread contamination within the cabins. The mean concentration of PCE was 10.12 μg/m3, exceeding the 2.06 μg/m3 observed in residences in a previous study. The positive matrix factorization (PMF) model was used to identify potential sources of PCE in cabins. Six categories of sources were determined, including in-cabin cleaning products, aircraft cleaning/maintenance, cabin interior material, aircraft and vehicle exhaust, non-fuel oil and ozone-associated chemical reactions. The biggest PCE source in cabins was attributed to in-cabin cleaning products (45.30%), followed by cabin interior materials (24.90%), and aircraft cleaning/maintenance (19.82%). The findings of this study are beneficial to improving aircraft cabin air quality, reducing harmful pollutant exposure for cabin crew and passengers.

Acoustical properties of the new sandwich structures for aircraft cabin interiors with integrated vacuum insulation

AbstractAny modern passenger aircraft must provide a high level of comfort for passengers who spend considerable time inside the cabin. The cabin's climate and interior noise levels contribute to this comfort. Vacuum insulation panels (VIP) have been explored as insulation materials to improve these factors due to their extremely low thermal conductivity. When integrating VIPs into the aircraft cabin's interior, it was discovered that the thermal conductivity of the entire sandwich structure was 3–6 times lower than conventional structures. This finding has generated much interest in using VIPs for aircraft cabin insulation. This article delves into the acoustic properties of these new structures featuring integrated VIPs. Tests were carried out to analyze the sound insulation capabilities of these structures. The results showed that the new interior structures exhibited promising acoustic properties.

Automatic assembly of in-cabin components based on hybrid guidance of binocular vision and laser tracker

In order to automate the assembly of a certain type of missile cabin interior components, a new assembly method with a mixture of binocular vision and laser tracker is proposed. The laser tracker is used to determine the coarse position and posture relationship between the cabin segment and the robot. The two binocular vision systems use skeleton extraction and hit-and-miss transformation to extract target cross-hatch features, perform pose fitting, and obtain the fine pose relationship between the target and the component. Twenty full-process simulations are performed on the CoppeliaSim platform. The results show that, with a pixel accuracy of 0.053 mm, the mean value of the position error of the assembly is 0.614 mm with a standard deviation of 0.270, and the mean value of the posture angle error of the assembly is -0.036° with a standard deviation of 0.178. This method realizes automatic grasp-release action and improved absolute positioning accuracy of the robot in the uncalibrated case and can meet the automation and precision needs of production in the final assembly plant.

Measurement uncertainty of vertical combustion test of civil aircraft interior materials

The civil cabin interior materials vertical combustion test is the necessary test to verify the flame retardancy ability of the floor coverings, textiles, seat cushions and cushions. It is an inspection step required for cabin interior materials before installation, which is of great significance for the safe flight of civil aircraft. During the experiment process, variable factors such as personnel and equipment are highly likely to impact the test results. To ensure the reliability of test results, it is necessary to summarize and evaluate the factors that may affect the results of the test process. Thus, in this paper, the test method, measurement model, and sources of measurement uncertainty have been analysed, and the calculation case of experimental measurement uncertainty has been introduced.

Investigation of Thermal Similarity and Performances of Solar Thermal Air Collector with Heat-Soaked Vehicle Cabin

This article explores the potential of vehicle interiors, which can reach temperatures of up to 120°C due to solar exposure, as efficient solar collectors. Comparative studies have been conducted on the thermal behavior of heat-soaked vehicle cabins and dedicated solar collectors, highlighting their potential benefits in heating, cooling and ventilation. Thermal soak tests reveal a remarkable similarity in thermal performance between the two, with minor temperature variations of up to 5.3°C between the equivalent components. These temperature deviations are mainly due to differences in absorptivity characteristics, in which the black absorber plate exhibits superior absorption capabilities compared to the grey interior cabin surfaces. Integration of ambient air through the inlets on the cabin floor helps with initial cooling of the hot soaked cabin. The collector benefits from a preheated air mixture (comprising heat-soaked cabin air and ambient air), which improves its operating temperatures. This characteristic is attributed to the synergistic integration of the two systems. By decoupling these systems and aligning the properties of the absorber plate, the cabin and the collector could become thermally identical. The potential of the heated vehicle cabin as a power generation source is underscored, which presents opportunities to supplement the energy demand in remote locations. This study illuminates the untapped potential of vehicular solar heat capture, highlighting its feasibility, diverse applications, and significant implications for sustainable energy strategies and community development.

Study on load characteristics and structural impact response propagation law of cabin internal explosion

Aiming at the problem that the distribution of explosion load in the cabin and the propagation law of structural impact response was unclear, this paper established the numerical calculation model of explosion in a closed cabin by ALE (Arbitrary Lagrangian Eulerian) method. There was an apparent convergence of shock waves at the cabin's corners, and the pressure relief hole's area and its position significantly affected the peak of quasi-static pressure. The peak acceleration of the deck structure decreased exponentially as the distance from the location of charge increased. Peak acceleration decreased by approximately 50% for each bulkhead crossing. There was a “paper window effect” during the cabin interior explosion on the whole ship. It meant there was a limit to the value for the energy generated by the explosion to be transmitted along the frame structure. When the charge was 150 kg, it reached the limit of the energy transferred by the structure in this paper. The response of the distant structure did not change significantly with the increase in the charge quality. The research revealed the impact response propagation mechanism in the structure and provided a reference for designing protective structures.

Thermo-Physiological Responses of Sailors in a Disabled Submarine With Interior Cabin Temperature and Humidity Slowly Rising As Predicted by Computer Simulation Techniques <br>

Thermo-Physiological Responses of Sailors in a Disabled Submarine With Interior Cabin Temperature and Humidity Slowly Rising As Predicted by Computer Simulation Techniques <br>

The Zwicker's psychoacoustic annoyance models for noise-induced discomfort in the electric vehicle cabin

Acoustic comfort has become an essential feature with the rapid development of the electric vehicle (EV) industry. As a representative nonlinear model, Zwicker's psychoacoustic annoyance (PA) model and a series of modified ones are established to evaluate the acoustic comfort of different products. However, whether these PA models apply to the noise-induced discomfort in the EV cabin remains uncertain. We investigated the psychoacoustic metrics and subjective discomfort of the EV cabin noise running at various speeds from 10-110km/h under four typical road conditions, i.e., asphalt, concrete, gravel, and bump. Thirty subjects rated the discomfort caused by 16 noise stimuli on the standardized 0-10 point numerical scale. The correlation and partial correlation analysis confirmed that the loudness of EV cabin noise dominated, and roughness and sharpness significantly influenced the discomfort. We identified that the original Zwicker's PA model performed well in evaluating the discomfort caused by the EV cabin interior noise and proposed a modified Zwicker's PA model that would be appropriate. Keywords: Electric vehicle, Cabin noise, Psychoacoustic annoyance, Noise discomfort, Sound quality

Application of acoustic metamaterial for tire noise reduction

Increased traffic volume leads to increased noise emitted by the vehicles. Additionally, the lightweight design of vehicles worsens the noise, vibrations and harshness behavior. The total noise of the vehicle consist of multiple sources. We focus on the influence of sound emitted by the tire on the interior cabin noise and on the pass-by noise. To address the problem, we develop two different wheelhouse liners based on a compound material and an acoustic metamaterial, respectively. The compound material consists of porous layers as well as a microperforated panel. The acoustic metamaterial relies on a periodic arrangement of local resonators. Both materials are numerically modeled and experimentally validated. We first measure the absorption coefficient of the liner in the Alpha Cabin. We then mount the liner to a vehicle and subsequently measure the performance of the full vehicle. We achieve improved performance in terms of sound attenuation and thus are able to reduce both, the cabin noise and the pass-by noise, significantly.

Determining mechanical and acoustical behaviors of all-recycled PP sandwich structures with bi-directional sinusoidal corrugated core

By recycling the waste polymer material and using it in weight reduction studies of electric vehicles, a double-sided gain is achieved against environmental pollution. Sandwich structures with prismatic cores obtained by recycling waste polymers can be used in structural applications of light and heavy commercial vehicles and public transportation vehicles that carry cargo and passengers. These sandwich vehicle parts could help to increase the max. range and load-carrying capacity of electric vehicles. In this study, sandwich plates with prismatic egg-box cores were produced with waste Polypropylene. Since the materials are collected from different waste sources, the physical properties (additive ratio, secondary substance determination, density) of the recycled material were measured. Thereafter, hardness, quasi-static flatwise and edgewise compression, and 3-point bending tests were done to determine the mechanical properties of the structure. After that, dynamic compression and 3-point bending tests were performed to determine the strength and impact energy absorption capacity of the structure in collision situations. Finally, impedance tube tests were carried out for the acoustic characterization, which is one of the important parameters affecting interior cabin comfort, and Sound Transmission Loss (STL) and Sound Absorption Coefficient (SAC) values of the structure were determined.

A novel design of heating system using phase change material for passenger car cabin in cold starting conditions

In this paper, the use of exhaust waste heat energy stored in a latent heat thermal energy storage (LHTES) system for cabin heating of a passenger car at cold climate conditions was investigated by experimental and computational fluid dynamics (CFD). A liquid circulation system was installed for this purpose, consisting of two heat exchangers, one in the passenger car's rear compartment and the other in which the phase change material (PCM) in the LHTES system was stored. Commercial RT55 paraffin wax was used as PCM, and tap water was used as heat transfer fluid (HTF). Experimental and CFD analysis studies, which started at 283 K cabin interior temperature, were continued for 1500 sec (25 min). Before the experiments, the cabin interior of the passenger car was cooled up to 283 K with the air conditioning system, and the air conditioning system was kept on at a setting where the cabin interior temperature would remain constant at 283 K during the experiments. Thus, real cold climate conditions were provided for the experimental study. As a result, it has been observed that with the new cabin heating system, thermal comfort conditions for people are provided after the first five minutes, and this temperature can be maintained throughout the experiment. So much so that the cabin temperature increased from 283 K to 295 K in five minutes and reached approximately 297 K at the end of the experiment with a slow rate of increase. Furthermore, the difference in RT55 temperatures between the experimental and CFD analysis results is less than 3% during the cabin interior heating period.

Agro-waste-based polymeric composite laminates for aerospace cabin interior and identification of their optimal configuration

Agro-waste-based polymeric composite laminates for aerospace cabin interior and identification of their optimal configuration

Stability of SARS-CoV-2 on Commercial Aircraft Interior Surfaces with Implications for Effective Control Measures.

The COVID-19 pandemic from 2019 to 2022 devastated many aspects of life and the economy, with the commercial aviation industry being no exception. One of the major concerns during the pandemic was the degree to which the internal aircraft environment contributed to virus transmission between humans and, in particular, the stability of SARS-CoV-2 on contact surfaces in the aircraft cabin interior. In this study, the stability of various major strains of SARS-CoV-2 on interior aircraft surfaces was evaluated using the TCID50 assessment. In contrast to terrestrial materials, SARS-CoV-2 was naturally less stable on common contact points in the aircraft interior, and, over a 4 h time period, there was a 90% reduction in culturable virus. Antiviral and surface coatings were extremely effective at mitigating the persistence of the virus on surfaces; however, their benefit was diminished by regular cleaning and were ineffective after 56 days of regular use and cleaning. Finally, successive strains of SARS-CoV-2 have not evolved to be more resilient to survival on aircraft surfaces. We conclude that the mitigation strategies for SARS-CoV-2 on interior aircraft surfaces are more than sufficient, and epidemiological evidence over the past three years has not found that surface spread is a major route of transmission.

Airborne and Structure-Borne Noise Control in the MB Truck Cabin Interior by the Noise Reduction in the Transmission Path

Airborne and Structure-Borne Noise Control in the MB Truck Cabin Interior by the Noise Reduction in the Transmission Path

A hybrid transfer function procedure for broadband auralization within small flight vehicle interiors

Auralization of the sound fields within flight vehicle interiors is of interest to aircraft designers considering crew and passenger ride quality. Computer models can be used to predict the filtering effects that the fuselage structure and interior volume have on the exterior sound field in order to simulate the resulting cabin interior noise. However, this can become expensive when a wide frequency range of analysis suitable for passenger auralization is desired. This is particularly the case when using deterministic modeling methods such as finite element analysis (FEA) wherein prohibitively high levels of detail and finite element discretizations are required to resolve the wavelengths at high frequencies. On the contrary, Statistical Energy Analysis (SEA), while not capturing important modal behaviors at low frequencies, is better suited for higher frequency analyses where structural and interior dynamics exhibit high modal overlap and spatially averaged physical quantities suffice. For this reason, a hybrid procedure is considered here that utilizes FE modal solutions at lower frequencies and SEA results at higher frequencies. A transfer function dataset containing the exterior to interior vibroacoustic filtering effect is calculated accordingly and subsequently stored to be used for a variety of exterior dynamic load cases. At low frequencies, the transfer function dataset detail is related to the level of

Numerical Analysis of Wind Noise Transmission through BEV Underbody

In electrified automobiles, wind noise significantly contributes to the overall noise inside the cabin. In particular, underbody airflow is a dominant noise source at low frequencies (less than 500 Hz). However, the wind noise transmission mechanism through a battery electric vehicle (BEV) underbody is complex because the BEV has a battery under the floor panel. Although various types of underbody structures exist for BEVs, in this study, the focus was on an underbody structure with two surfaces as inputs of wind noise sources: the outer surface exposed to the external underbody flow, such as undercover and suspension, and the floor panel, located above the undercover and battery. In this study, aero-vibro-acoustic simulations were performed to clarify the transmission mechanism of the BEV underbody wind noise. The external flow and acoustic fields were simulated using computational fluid dynamics. The vehicle structural vibration and sound fields of the interior and exterior cabin were analyzed using vibroacoustic models consisting of three subsystems modeled by the finite-element or boundary-element method: The first is an underbody structure finite-element model containing a white body, suspension, battery, and undercover; the second is the interior cabin space boundary-element model; the third is the exterior cabin space finite-element model for analyzing acoustic radiation resulting from vehicle structural vibration for the small space between the floor panel and battery, the motor room and the under-vehicle space between the ground and undercover. The analysis results using the vehicle model reveal that the pressure fluctuations acting on the floor panel are more-dominant inputs for cabin noise than those acting on the outer surface. The pressure fluctuation acting on the floor panel is affected by the acoustic mode of the space between the battery and the floor panel.

An Efficient Hybrid Computational Process for Interior Noise Prediction in Aeroacoustic Vehicle Development

Numerical methodologies for aeroacoustic analyses are increasingly crucial for car manufacturers to optimize the effectiveness of vehicle development. In the present work, a hybrid numerical tool based on the combination of a delayed detached-eddy simulation and a finite element model, which relies on the Lighthill's acoustic analogy and the acoustic perturbation equations, is presented. The computational aeroacoustics is performed by the software OpenFOAM and Actran, concerning respectively the CFD and the FEM. The aeroacoustic behavior of the SUV Lamborghini Urus at a cruising speed of 140 km/h has been investigated. The main aerodynamic noise phenomena occurring in the side mirror region in a frequency range up to 5 kHz are discussed. The numerical simulations have been verified against the measurements performed in the aeroacoustic wind tunnel of the University of Stuttgart, operated by FKFS. The predicted exterior noise propagation into the far field has been validated by comparing the sound pressure level with the experimental data measured by exterior microphones, which were located outside the turbulent region beside the wake of the side mirror. Furthermore, the noise transmission into the cabin through the side window has been modeled. Simulation results have been validated by means of interior microphones installed on the driver seat. Both the exterior and the interior noise predictions show very good correlations with experiments. Lastly, a comprehensive investigation of the most critical aeroacoustic sources has been carried out. The numerical tool has been proven to be in good accordance with the microphone array with respect to the distribution of the sound pressure level in the proximity of the side mirror. Besides, the main vortex structures involved in the generation mechanisms of wind noise have been investigated by a CFD analysis. The entire CAA process has been proven to be accurate and suitable for combined analysis between the generation mechanisms of wind noise and the resulting transfer into the interior cabin to the driver's ear as well.

SYNTHESIS AND CHARACTERIZATION OF MECHANICAL AND PHYSICAL PROPERTIES OF FALSE BANANA (ʾƏNÄSÄTƏ) FIBER REINFORCED COMPOSITE MATERIAL

The use of environmentally friendly materials has recently been promoted due to increased awareness of environmental issues. To offer a better world for future generations, we must decide what we will utilize and serve today. When resources and products reach the end of their useful lives, resource preservation and degradation become issues. Biodegradable products manufactured from renewable resources address these issues. This research aims to develop a biodegradable resource of false banana (ʾənäsätə) fiber as reinforcement with polyester resin composite material manufactured by hand layup method at room temperature. The mechanical and physical properties of the produced sample were investigated. include tensile, flexural, impact strength, and water absorption. The fiber surface was treated with NaOH alkaline in distilled water solution. In composites, the fiber orientations were 0o, 90o, 45o/-45o, 0o/90o, and chopped, at 40% fiber volume fraction. The sample's production process was performed successfully. A chopped sample is an easier manufacturing process relative to the other. As the result, 0o fiber direction scored the highest tensile strength, which is 181.41MPa. In the flexural and impact strength test, a 90o oriented fiber was observed with the highest value, which is 81.43 MPa and 9.75 joules, respectively. The samples were immersed in distilled water until saturated. The highest percentage of water absorption was 45o/-45o oriented fiber. Many researchers have recently shown interest in natural fiber composites material for aerospace and automotive applications, such as aircraft radomes and interior cabin components, as well as remarks on natural fiber composites' future trends and problems. This article provides readers with a positive perspective and piques industry players' interest in the potential of using natural fiber composites in aerospace applications to improve current aerospace material performance, particularly in terms of lightweight and environmental sustainability. Keywords: Composite, Fiber, Manufacturing, Matrix, Reinforcement, Sustainability

Evaluation of high-speed aircraft thermal management system based on spray cooling technology: Energy analysis, global cooling, and multi-objective optimization

With the increase in aircraft speed, the aerodynamic heating on the aircraft wall has become one of the key factors restricting flight safety. Although passive thermal protection can solve the thermal protection problem of the aircraft body, there will always be some heat transferred into the cabin. And the temperature of the cabin interior environment and cabin wall increases, which reduces safety. The spray cooling system with R134a as a coolant can reduce the cabin wall temperature to 275 K, and the temperature drop rate can reach 1.05 K/s, so that the cabin cooling needs can be realized. The refrigeration system is used to connect the spray system with the fuel loop to form the closed-air spray cooling heat management system of the aircraft. The refrigeration system and the tandem radiator are optimized according to the genetic algorithm. After repeated iterations with different design parameters, the exergy efficiency and COP of the refrigeration system can reach 80 % and 2.36, and the pressure loss and the bottom plate temperature of the microchannel heat exchanger are 0.98 Mpa and 313 K, respectively. According to the analysis of the efficiency of the heat management system, the ejector efficiency, the energy efficiency ratio (EER) of the total system, and the required primary fluid flow rate, the required primary flow rate is at least 0.0027 kg/s to drive the thermal management system, EER of high-speed aircraft thermal management system can reach 15.62 %, exergy efficiency of the refrigeration system and the ejector efficiency can reach 44 % and 1 4% respectively.

The prediction of autonomous vehicle occupants’ pre-crash motion during emergency braking scenarios

This research investigates a computational method, which can assist the development of occupants’ passive safety in future autonomous vehicles, more particularly in the definition of head kinematics in rotated seat arrangement during emergency braking. To capture these head motions, the methodology utilised an Active Human Model, whose head kinematics were validated in a previous work in three-point and lap-belt restraint configuration scenarios. A sled model was then built where the seat backrest angle (SBA) and the seat orientation, modelled by rotating the acceleration angle (AA), could be adjusted to represent various ‘living room’ seating conditions. A Design of Experiments study was then performed by varying AA from 0° to 360° in steps of 22.5° and SBA from 20° to 60° in steps of 8°. The responses were subsequently converted into a Reduced Order Model (ROM), which was then successfully validated through a comparison with the kinematic responses predicted with simulations. In terms of simulation time, it was found that the ROM was able to calculate the head kinematics in 3 s instead of the 1.5 h taken using Simcenter Madymo, without compromising predicted responses accuracy. This research has provided a unique method to define head kinematics corridors for seated occupants in autonomous vehicle interiors, including maximum head excursion, head kinematics as a function of time and define for the first time (a) the safe “or’ but not both head envelope within the cabin interior, and (b) capture the seated scenarios where head proximity to airbag systems could be of concern, following emergency braking.