Passenger Car Model Research Articles

Tailpipe emission from petrol driven passenger cars

Realizing the dominance of petrol-driven passenger cars of MUL over the fleet of cars in India, a case study of different models of petrol-driven passenger cars of Maruti reporting at an authorized service station of M/s R.K.B.K. Automobiles, Gorakhpur was taken up and the tailpipe emissions along with individual vehicle-related parameters were monitored for idle and fast idle test conditions. The outcome of the study relating to the effect of various vehicle-related parameters on CO and HC emissions of petrol-driven passenger cars of Maruti has led to the useful inferences, which can be used not only for predicting the emission of vehicles with respect to vehicle age and mileage, but also for automobile manufacturing sector to help them produce such environmentally benign petrol-driven passenger cars having long-lasting compliance of pollution control systems with respect to vehicle age and mileage of the petrol-driven passenger cars in the country.

Transport Logistics Optimization Model Of Passenger Car Based On Heuristic Algorithm

Passenger car logistics transportation problem is at the primary stage of development in China, great economic loss and waste of resources caused in the process of logistics transportation, because most of enterprises in China rely on artificial experience for guidance at present. And use of a particular genetic algorithm to solve this problem by previous also exist many defects, such as programming complexity, instability and low efficiency etc. In view of this, The heuristic algorithm designing based on the greedy thought and the 0-1 knapsack thought was proposd, according build a universal model of the logistics transportation to the passenger car.Experimental results show, this model not only recording the concrete scheme of loading,also can make the optimization by changing the loading sequence. etc. This model is applicable to solve similar problems of transport logistics, and containing great practical application value and economic value.

Computation-based Dynamic Driving Simulation for Evaluation of Mountain Roads with Complex Shapes: A Case Study

Lower standard rural roads with a design speed less than 40km/h account for more than 80% of total roadway network in China. In most situations, vehicles on these rural roads are of free traffic flow, and the driving stability of a vehicle is therefore mostly influenced by alignments and road surface. Single-vehicle run-off-road crashes are often associated with poor road conditions. Therefore, the improvement of alignment design of the roads can be effective to reduce the number of traffic accidents. This research targets at the analysis of driving in several sections of a four-class rural road in Yunan province, China, with varying alignments and complex shapes. In this context, a road creation module, a vehicle dynamics model, and driver module are established in computing environment, and integrated into a “roadway-driver-vehicle” virtual driving system. Driving simulations of a passenger car model on the test segments are conducted. Speed, driver workload, and ride comfort are analyzed in relation to varying geometric alignments. The simulation results show that: by balancing the design parameters of adjacent curve radii and the tangent length in-between, critical safety driving speed on lower standard rural roads can be obtained; the use of hairpin curves and the absence of spirals would lead to a rapid increase in both angular speed of steering wheel and lateral acceleration change rate, resulting in increasing driver nervousness and passenger discomfort.

Experimental and Numerical Aerodynamic Analysis of a Passenger Car: Influence of the Blockage Ratio on Drag Coefficient

Experimental and numerical investigations were performed to determine the pressure distributions and the drag forces on a passenger car model. Experiments were carried out with 1/5th scale model FIAT Linea for 20% and ~ 1% blockage ratios in the Uludag University Wind Tunnel (UURT) and in the Ankara Wind Tunnel (ART), respectively. Computational fluid dynamics (CFD) analysis for 1/5th scale model with 0%, 5%, and 20% blockage ratios was performed to validate various blockage correction methods supplementary to the experimental results. Three-dimensional, incompressible, and steady governing equations were solved by STAR-CCM+ code with realizable k–ε two-layer turbulence model. The calculated drag coefficients were in good agreement with the experimental results within 6%. Pressure coefficients on the model surfaces have shown similar trends in the experimental and numerical studies. Some of the existing blockage correction methods were successfully compared in this study and predicted drag coefficients were within ± 5%. The authors propose the continuity and the Sykes blockage correction methods for passenger car models because they are very simple and practical and they can be used economically for engineering applications.

Transient thermal model of passenger car's cabin and implementation to saturation cycle with alternative working fluids

A transient thermal model of a passenger car's cabin is developed to investigate the dynamic behavior of cabin thermal conditions. The model is developed based on a lumped-parameter model and solved using integral methods. Solar radiation, engine heat through the firewall, and engine heat to the air ducts are all considered. Using the thermal model, transient temperature profiles of the interior mass and cabin air are obtained. This model is used to investigate the transient behavior of the cabin under various operating conditions: the recirculation mode in the idling state, the fresh air mode in the idling state, the recirculation mode in the driving state, and fresh air mode in the driving state. The developed model is validated by comparing with experimental data and is within 5% of deviation. The validated model is then applied for evaluating the mobile air conditioning system's design. The study found that a saturation cycle concept (four-stage cycle with two-phase refrigerant injection) could improve the system efficiency by 23.9% and reduce the power consumption by 19.3%. Lastly, several alternative refrigerants are applied and their performance is discussed. When the saturation cycle concept is applied, R1234yf MAC (mobile air conditioning) shows the largest COP (coefficient of performance) improvement and power consumption reduction.

Crashworthiness design for functionally graded foam-filled bumper beam

Automotive bumper beam is an important component to protect passenger and vehicle from injury and damage induced by severe collapse. Recent studies showed that foam-filled structures have significant advantages in light weight and high energy absorption. In this paper, a novel bumper beam filled with functionally graded foam (FGF) is considered here to explore its crashworthiness. To validate the FGF bumper beam model, the experiments at both component and full vehicle levels are conducted. Parametric study shows that gradient exponential parameter m that controls the variation of foam density has significant effect on bumper beam’s crashworthiness; and the crashworthiness of FGF-filled bumper beam is found much better than that of uniform foam (UF) filled and hollow bumper beam. The multiobjective optimization of FGF-filled bumper beam is also performed by considering specific energy absorption (SEA) and peak impact force as the design objectives, and the wall thickness t, foam densities ρf1 and ρf2 (foam densities at the end and at mid cross section, respectively) and gradient exponential parameter m as design variables. The Kriging surrogate modeling technique and multiobjective particle swarm optimization (MOPSO) algorithm were implemented to optimize the FGF-filled bumper beam. The optimized FGF-filled bumper beam is of great advantages and it can avoid the harmful local bending behavior and absorb more energy than UF filled and hollow bumper beam. Finally, the optimized FGF-filled bumper beam is installed to a passenger car model, and the results demonstrate that the FGF-filled bumper beam ensures the crashworthiness performance of the passenger car while reduces weight about 14.4% compared with baseline bumper beam.

IIHS 풀 오버랩 범퍼 시험 대응 범퍼 백빔 중앙 보강재 설계

Since 2007, Insurance Institute of Highway Safety(IIHS) has conducted the new bumper test using bumper barrier to estimate the repair cost of impacted vehicle. In this study, for the front body FE model of a medium size passenger car analyzes were carried out to optimize the shape of backbeam center reinforcement bracket. First, overlap effect was examined with changing the overlap magnitude and spot welds were added along the backbeam center line for reducing the section shear deformation. Next, for an overlap model design parameter study was performed for the bracket. Thickness effect was examined and an inner reinforcement was added to the bracket. Also, the lower part of bracket was deleted and additionally the bracket length was extended. The results were discussed in terms of backbeam backward deflection, barrier backstop intrusion and weight. Compared with the current design, the final model showed 44.1% bracket weight reduction with 30.0% decrease of backbeam deflection.

Detection of traffic sound for driving safety: Effects of car body sound insulation

Hearing is an important physiological function that humans rely on to sense the surrounding situations. It is well understood that acoustic cues are critical for pedestrians, bicycle and motorcycle riders to identify traffic, thus to avoid potential risks in a timely manner. Similarly, efficient and accurate perception of external acoustic warning signals (e.g., car horn and siren sounds) in the traffic environment are also important for driving safety. As modern vehicles are made more and more sound proofing, mainly for the sake of riding comfort, it is increasingly difficult for drivers to hear external sounds, which can impair the driver's hearing perception and detection of potential danger posed by nearby traffic through natural hearing. Currently, there is a lack of research in the literature regarding the relationship between the sound perception capability by drivers and driving safety. Therefore, this study focuses on investigating how well the acoustic warning signals in the surrounding traffic environment can be perceived by the driver under various conditions and its potential influences on driving safety. To correlate the effectiveness of drivers detecting the external traffic sound to the sound isolation level of the car body, the sound insulation performance of two selected passenger car models and the subjective sound localization accuracy through vehicle structures are measured. It is found that the existence of the car body, more specifically the car body sound insulation effect, noticeably degrades the sound localization accuracy of drivers. In addition, the perceived sound source direction is found to shift toward the side of the car body with lower sound insulation performance.

Indirect method for wheel–rail force measurement and derailment evaluation

Wheel set flange derailment criteria for railway vehicles are derived and the influence of wheel–rail contact parameters is studied. An indirect method for wheel–rail force measurement based on these derailment evaluation criteria is proposed. Laboratory tests for the calibration of strain–force devices on the bearing box are carried out to determine the relationship between the applied force and the measured strain. The simulation package, SIMPACK, is used to develop a passenger car model to generate wheel–rail forces and vibration signals. Different cases are considered in this model to provide an accurate validation of the identified wheel–rail forces. A feasibility test is conducted in the Beijing Loop test line using a passenger car equipped with a set of strain gauges on the wheel set. The comparison of the force time history applied to the instrumented wheel set and that obtained using the indirect method is presented.

Passenger Car and Truck Operating Speed Models on Multilane Highways with Combinations of Horizontal Curves and Steep Grades

Operating speed prediction models have been proposed as a candidate method to assess design consistency on highways and streets. A significant number of operating speed prediction models exist for passenger cars on two-lane rural highways. Few models exist for passenger cars on multilane highways, while the literature is scant for operating speed models for trucks on multilane highways. This research uses a systems modeling approach to predict passenger car and truck operating speeds on multilane highways with combinations of horizontal curves and steep vertical grades. Mean operating speeds were modeled as a function of several geometric design features and the traffic control devices present at each study site. Further, the possible endogenous relationship between passenger car and truck speeds was investigated. The findings indicate that the radius of horizontal curve appears to have a larger influence on passenger car operating speeds than truck speeds. Vertical grades appear to have a more significant influence on truck operating speeds than on passenger car speeds. Increasing the right shoulder width is associated with higher passenger car operating speeds, but the lane width was not statistically significant in the passenger car speed models. Increasing the lane width, however, was associated with higher truck operating speeds; the right shoulder width was not associated with truck operating speeds. Higher posted speed limits were associated with higher truck and passenger car operating speeds. An endogenous relationship between truck and passenger car operating speeds was found.

Factors of Product Customization for the 1200cc Passenger Car Segment: An Empirical Study in Central India

Increasing competition in the automobile market has put a great challenge before car companies to cater to the specific needs of the customers in order to remain in business. The growing competition also requires frequent innovations in the industry. High cost associated with frequent innovations may cause big setbacks to these companies if any new launch of a passenger car model fails to attract the customers' attention. A precise model specification, catering to the needs and aspirations of the customers, is ,therefore, required. This paper is an effort to find out the factors that help the companies to customize their products as per varied customer needs, categorized on the basis of their socioeconomic classes such as age, city, occupation, income group, and their present car ownership status. The study investigated selected twenty variables as determinants of the customers' choice for the selection of a 1200cc car. Factor analysis (on the influencing variables) out of the said twenty variables was applied to the respective categories of customers. The analysis found varying factors that contributed differently in the customers' choice while selecting a 1200cc car. Considering these factors and their contribution, the passenger car companies, especially in the 1200cc segment, can incorporate appropriate specifications for innovation in their products.

Optimization and Matching of Mini Passenger Car Suspension Parameters Based on DOE

The traditional way of the matching between suspension parameters and vehicle performance is that we assess the matching of suspension design parameters through the driver's subjective experience, this will lead that the vehicle development cycle is long and high cost, meanwhile the matching during the parameters of suspension is blindness. With the development of computer technology, combining the modern design theory and virtual prototyping technology, based on multi-body system dynamics method, the virtual prototyping model of mini passenger car was built. By using understeering degree, roll rate and total RMS acceleration values as evaluation indexes, the orthogonal experiment was designed and the range analysis was carried out, and the effects of the suspension structure parameters on handling stability and riding such as suspension rate of front suspension and rear suspension, torsion stiffness of antiroll bar, damping ratio of front suspension and rear suspension and so on were studied. Then the remarkable factors are found, the final results supply guidance and support for the optimization of the suspension parameters.

Drag Reduction of Passenger Car Using Add-On Devices

This work proposes an effective numerical model using the Computational Fluid Dynamics (CFD) to obtain the flow structure around a passenger car with different add-on devices. The computational/numerical model of the passenger car and mesh was constructed using ANSYS Fluent which is the CFD solver and employed in the present work. In this study, numerical iterations are completed, and then aerodynamic data and detailed complicated flow structure are visualized. In the present work, a model of generic passenger car was developed using solidworks, generated the wind tunnel, and applied the boundary conditions in ANSYS workbench platform, and then testing and simulation have been performed for the evaluation of drag coefficient for passenger car. In another case, the aerodynamics of the most suitable design of vortex generator, spoiler, tail plates, and spoiler with VGs are introduced and analysed for the evaluation of drag coefficient for passenger car. The addition of these add-on devices are reduces the drag-coefficient and lift coefficient in head-on wind. Rounding the edges partially reduces drag in head-on wind but does not bring about the significant improvements in the aerodynamic efficiency of the passenger car with add-on devices, and it can be obtained. Hence, the drag force can be reduced by using add-on devices on vehicle and fuel economy, stability of a passenger car can be improved.

Rollover crashworthiness analysis of a railroad passenger car

Rollover of railroad passenger cars is one of the most serious accidents having high rates of injuries and fatalities. Therefore, the railroad passenger car structures should satisfy the rollover crashworthiness requirements in order to protect the occupants. In this paper, rollover crashworthiness of a railroad passenger car called ‘N13-type’ used by Turkish State Railways is investigated. To assess the rollover crashworthiness, rollover simulations of the full scale and detailed passenger car models onto a rigid ground are completed by using a non-linear explicit finite element code, Abaqus. The numerical model is validated with static and modal experimental measurements before running rollover analyses of the railroad passenger car. Good agreement is observed between tests and finite element results, which indicate that the numerical model accurately represents the real structure. Simulations are performed in accordance with the regulation of ECE R66. Based on this standard, two different rollover scenarios are considered. In the first scenario, lateral rollover simulation is performed at the standard angular velocity due to ECE R66 regulation. The second scenario is performed at the double of this angular velocity to investigate the crashworthiness behaviour under exaggerated conditions. As a result of the analyses, it is observed that the residual space remains undamaged during and after the rollover, and passenger car is able to pass the required regulations.

Low-Wind-Drag Numerical Research on Fenders and Wheels of Car Model

In this paper,a simplified model of the car with low resistance was built and 3D numerical simulations have been finished with two schemes adopted :the rough model and the smooth model of fenders and wheels. The aerodynamic characteristics and the flow field structure of the passenger car model were obtained with CFD, then the affect of the fenders and the wheels to the aerodynamic resistance were analyzed. Seen from the results, minor warping of the fenders and the sharp corner of wheels induce great energy loss, while smooth modeling of these two parts ensures the flow fluent, and decreases the CD value. The aerodynamic characteristics and the results gained from this paper provide theoretical basis for the low-wind-drag car.

Comparative Study on External Flow Simulation of Passenger Car with Complex Underbody and Flat Underbody

In this paper, the external flow simulation has been carried out on a simplified passenger car model with two schemes adopted: a smoothed complex underbody and a flat underbody. The aerodynamic characteristics and the flow field structure of the passenger car model were obtained with CFD method, and the drag coefficients of the smoothed complex underbody and the flat underbody are respectively 0.275 and 0.251. According to the simulation, flow separation and energy loss of fluid was caused by protuberances on the complex underbody. As there are many differences between the aerodynamic characteristics of the smoothed underbody and the flat one, its suggested to use a smoothed complex underbody not a flat underbody in the studying of aerodynamic drag reduction of a passenger car.

Modeling of Railway Vehicles for Virtual Homologation from Dynamic Behavior Perspective

Modeling and simulation in railway vehicle dynamics is a useful tool in the design of rolling stock when choosing the best solutions for vehicle and infrastructure components in assessing possible risks and, more recently, in the certification of railway vehicles from the point of view of dynamic behavior based on virtual approval. This paper presents the discrete-continuous model of two-level suspension passenger car running along a tangent track with random vertical irregularity as the theoretical tool to asses the parameters of the approval criteria: the running behavior and comfort. The equations of motion are solved in frequency-domain using the modal analysis method and then the carbody acceleration and the comfort index are calculated. The results derived from a numerical simulation performed for the virtual homologation of a particular passenger car are presented, and so is the possibility to improve the design of the vehicle suspension, in compliance with the approval criteria.

Rear Seat Child Safety in Near-Side Impacts: A Modeling Study of Common Sitting Positions

Objective: The purpose of this study was to evaluate and propose improvements to the injury mitigation systems, in near-side impacts, for 6 common sitting positions of young adolescents using a previously validated model. Methods: The evaluation was made by using a model of a complete passenger car, including head and thorax–pelvis air bags, which was impacted laterally by a barrier in 2 load cases. The SID-IIs finite element model was used for the evaluations and was seated in 6 different positions in the rear outboard seat: the nominal anthropomorphic test device (ATD) position, 1 inboard position, 3 outboard positions, and 1 braking (forward) position. These positions have previously been identified as common sitting positions in awake and asleep children. The studied dependent variables were head injury criterion (HIC) 36, resultant head linear acceleration, resultant head rotational acceleration, chest viscous criterion, and chest deflection. Results: The lowest head injury measures were seen in the braking positions and in the nominal ATD position, and the highest were seen in the inboard and outboard positions. The lowest chest injury measures were recorded in the inboard and nominal ATD positions, and the highest were recorded in the outboard and braking positions. The occupant in the outboard positions interfered with the air bags during their deployment. The occupant in inboard and braking positions tended to push the curtain air bag over the windowsill. Conclusions: Studies that investigate the injury mitigation effects in common sitting positions, beyond the nominal ATD position, are essential to highlight means to provide improved and robust safety for child occupants. This study was based on the SID-IIs 5th percentile female, which has very similar anthropometry to a 50th percentile 12-year-old. Therefore, the conclusions of this study are applicable to many 11-year-olds up to young adolescents, as well as to small females. The outboard and inboard positions of this study resulted in the highest head injury measures. Although all of the injury measures were only slightly higher than the nominal position, the trends suggest that, in near-side impacts, these positions should be discouraged. The extensively outboard positions resulted in unfavorable air bag positioning during deployment. The inboard position resulted in head strikes further forward of the nominal one; the curtain air bags need inflated cells at all locations of head strike.

CFD Simulation for Flow over Passenger Car Using Tail Plates for Aerodynamic Drag Reduction

This work proposes an effective numerical model based on the Computational Fluid Dynamics (CFD) approach to obtain the flow structure around a passenger car with Tail Plates. The experimental work of the test vehicle and grid system is constructed by ANSYS-14.0. FLUENT which is the CFD solver & employed in the present work. In this study, numerical iterations are completed, then after aerodynamic data and detailed complicated flow structure are visualized. In the present work, model of generic passenger car has been developed in solid works-10 and generated the wind tunnel and applied the boundary conditions in ANSYS workbench 14.0 platform then after testing and simulation has been performed for the evaluation of drag coefficient for passenger car. In another case, the aerodynamics of the most suitable design of tail plate is introduced and analysedfor the evaluation of drag coefficient for passenger car. The addition of tail plates results in a reduction of the drag-coefficient 3.87% and lift coefficient 16.62% in head-on wind. Rounding the edges partially reduces drag in head-on wind but does not bring about the significant improvements in the aerodynamic efficiency of the passenger car with tail plates, it can be obtained. Hence, the drag force can be reduced by using add on devices on vehicle and fuel economy, stability of a passenger car can be improved.

Crash and structural analyses of an aluminium railroad passenger car

Crashworthiness, strength and vibrational features of a railroad passenger car, which is originally made of steel members and then converted to an aluminium design, are studied. The finite element (FE) method is utilised for the static analysis in compliance with various scenarios defined in UIC CODE OR 577, modal analysis and simulation of the crash into a rigid wall. Firstly, a full-length, detailed passenger car model made of steel is used in FE analyses and the model is verified for the steel car body by comparisons with strain measurements and experimental evaluation of natural frequencies. The agreement between test measurements and FE results indicates that the FE model of the railroad car accurately represents the original structure. Following, effects of material change on the structural behaviour can be accurately judged based on the outcomes of the analyses. It is observed that the stress values and natural frequencies of the aluminium structure are almost equal to those of the original steel structure. Moreover, the crash energy absorption characteristics are within the acceptable tolerances for both cases. The final aluminium design is found to be about one-third of the weight of the initial steel structure while it preserves stiffness values within acceptable limits. In addition, an equivalent spring-mass system is developed to model the crash of both steel and aluminium passenger cars, which can be used for occupant safety investigations in future.