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Fluid-Structure Interaction of a Spring-Mounted Symmetrical Rigid Wing for Drag Reduction of Cars at Higher Wind Velocities

Kingston University-George Haritos
University of Duisburg-Essen-Simon Fels
  • Technical Paper
  • 2020-01-5037
Published 2020-03-10 by SAE International in United States
This paper details an aeroelastic concept for an adaptive and passive wing, which is primarily aimed for use within the automotive sector to reduce drag and fuel emissions. The work will also be of interest in the motorsport sector to improve performance and also some applications within the aerospace and renewable energy sectors. The wind tunnel testing of a spring-mounted symmetrical NACA 0012 wing in freestream is studied over 0° to 40° angles of incidence. General operation of the concept is verified at low angles in the pre-stall region with that of a theoretical estimation using finite and infinite wings. Three distinct regions are identified, pre-stall, near-stall, and post-stall. The transient limitations associated in the near-stall region with variations in spring loading and flow velocities are discovered. It is identified as a periodic self-sustained oscillation with nondimensional reduced frequencies in the range from 0.14 to 0.22. Furthermore, performance in the post-stall region along with pre-stall is reported, and methods for the adjustment of the elastic element for a desired response are introduced. Evaluation is conducted…
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Influence of Nano Alumina Oxide Addition on the Performance of Diesel Engine Fueled with Nonedible Oil Biodiesel-Butanol Blends

Hindustan Institute of Technology and Science-B. Prabakaran
  • Technical Paper
  • 2020-01-5036
Published 2020-03-10 by SAE International in United States
Biodiesel and butanol are best-suited liquid fuels to fuel compression ignition engines. This experimental study is to investigate the effects of nano alumina on the performance of a variable compression ratio engine fueled with biodiesel-butanol blends. The experiment was conducted in two stages: Arriving at an optimal blend of biodiesel and butanol from the property testing of the blends followed by fueling the optimal blend containing 50% biodiesel and 50% butanol with nano alumina in four proportions (25, 50, 75, and 100 ppm) variable compression ratio engine. The compression ratio was varied as 16:1, 19:1, and 20.5:1. The compression ratio of the engine was varied by the increase and decrease of the clearance volume as the engine used was a variable compression ratio engine. Nano alumina was blended with biodiesel-butanol blend by ultasonication. The results of the property testing showed that the addition of butanol into biodiesel reduced the kinematic viscosity, cetane number, flash point, energy content, and an increase in oxygen content and heat of vaporization. The addition of nano alumina into biodiesel-butanol blend…
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High-Fidelity Modeling and Prediction of Hood Buffeting of Trailing Automobiles

Honda R&D Americas, Inc.-Austin Kimbrell, Tyler Rupp, Peter Kang
The Ohio State University-Rodrigo Auza, Jack McNamara
  • Technical Paper
  • 2020-01-5038
Published 2020-03-10 by SAE International in United States
The importance of fluid-structure interaction (FSI) is of increasing concern in automotive design criteria as automobile hoods become lighter and thinner. This work focuses on computational simulation and analysis of automobile hoods under unsteady aerodynamic loads encountered at typical highway conditions while trailing another vehicle. These driving conditions can cause significant hood vibrations due to the unsteady loads caused by the vortex shedding from the leading vehicle. The study is carried out using coupled computational fluid dynamics (CFD) and computational structural dynamics (CSD) codes. The main goal of this work is to characterize the importance of fluid modeling fidelity to hood buffeting response by comparing fluid and structural responses using both Reynolds-Averaged Navier-Stokes (RANS) and detached eddy simulation (DES) approaches. Results are presented for a sedan trailing another sedan. Comparisons between RANS and DES emphasize the importance of turbulence modeling fidelity in order to capture the unsteadiness of the flow and the vibration response of the hood. These comparisons include analysis of the lift forces, pressure loads on the hood, power spectral density (PSD) analysis…
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Optimal Design for Maximum Fundamental Frequency and Minimum Intermediate Support Stiffness for Uniform and Stepped Beams Composed of Different Materials

Helwan University-Elsawaf Ahmed, Elsayed Tamer, Farghaly Said
  • Technical Paper
  • 2020-01-5014
Published 2020-02-06 by SAE International in United States
The minimum support stiffness that achieves the maximum modal frequencies or critical speed is very important in the design of mechanical systems. The optimal values of the intermediate support stiffness and geometrical parameters of uniform and stepped Timoshenko beams composed of single or two materials are studied in order to maximize the modal frequency and minimize the intermediate support stiffness. Dynamic stiffness matrix (DSM) method and multi-objective particle swarm optimization (MOPSO) algorithm are used together to evaluate new optimal parameters. For single material, the results show that for uniform thick beams, the optimal maximum fundamental frequency and minimum intermediate support stiffness are lower than those of Bernoulli-Euler beams. In addition, the optimal design for stepped beams made of two metallic materials is investigated. For three different metallic combinations, gain factors of 1.561 to 2.745 are obtained for a beam without intermediate support. Comparison with experimental results is carried out. The current study and its results can be applied to improve the dynamic performance of many of industrial applications, such as guyed masts derricks, vertical tube…
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Application of Factor Analysis in the Determination of Carburetor Icing Tendency in Aviation Gasoline, RON 97, RON 98, RON 100, and the Blends in Lycoming O-320 Engine

Royal Malaysia Police-Kumar Thanikasalam
Universiti Teknologi Malaysia (UTM)-Mohsin Rahmat, Abdul Majid Zulkifli, Abdul Ghafir Mohammad Fahmi, Manickam Wash Ananth
  • Technical Paper
  • 2020-01-6000
Published 2020-02-04 by SAE International in United States
Carburetor icing (CI) was the most commonly cited factors in general aviation accident category with 1,019 (34%) accidents. The objective of the study is to measure the CI tendency of selected fuels by the application of factor analysis (FA). All the test fuels were characterized based on chemical and physical properties of the fuels. Gas chromatographic (GC) analysis of the tested fuels were categorized based on hydrocarbon types and basic fuel properties. The study considered sixteen variables for CI assessment, using the selected and calculated fuel properties. Twenty-three aviation fuels from literatures were collected and, using FA, model equations explaining the CI tendency of the aviation fuels were derived, and their respective factor scores were calculated. The model was applied to the 14 fuels in this study, and their respective factor scores were calculated. All the fuels were ranked using the factor score from the best to worst. Brake-specific fuel consumption (BSFC) of the fuels was derived experimentally. FA results showed that FA explain 94.246% of the variance for CI. Best CI tendency was shown…
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Sound Quality Development Using Psychoacoustic Parameters with Special Focus on Powertrain Noise

Geely Powertrain Research Institute-Garanto Victor, Geng Zhirong, Hu Junfeng, Deng Xiaolong, Yang Wanli, Wang Hao
  • Technical Paper
  • 2020-01-5000
Published 2020-01-24 by SAE International in United States
This research uses vehicle interior noise at the driver position during full load acceleration to objectively define the resultant Sound Quality (SQ) of the vehicle analyzed by focusing on powertrain noise. A calculation method is developed to rank vehicles in order of customer preference (Sound Rank) and provide a subjective evaluation score for different error states a vehicle can encounter. In order to calculate these two scores, a pleasantness parameter is obtained using standard calculated psychoacoustic parameters with different weighting scores depending on their importance toward the preference ranking. Then pleasantness is correlated with jury test results and subjective evaluations.The results obtained show that the model is capable of quantifying the vehicle SQ during the vehicle development process and position a vehicle within a two-dimensional (2D) powerful-refined plot. This is achieved with the help of psychoacoustic parameter scatter bands. The model provides an objective tool to quantify and verify the resultant SQ to help meet and optimize Noise, Vibration, and Harshness (NVH) targets.
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An Efficiency-Based Hybrid Mode Selection Model for A P134 Plug-In Hybrid Powertrain Architecture

Borgward Automotive (China), LTD-Fangping Tan
Borgward Institute of Engineering-Erdong Yan
  • Technical Paper
  • 2020-01-5001
Published 2020-01-22 by SAE International in United States
With ever-stringent fuel economy requirements, hybrid powertrain technology has been widely adopted by automotive OEMs. There are many forms of hybrid powertrain architectures including new concept or developed to adapt to pre-existing engine or transmission systems. This study examined, in particular, the P134 hybrid architecture: topology, functional capabilities, and use cases in vehicle drive, defined hybrid powertrain operating modes, and developed an offline decision model based on given system characteristics: engine, e-motor, and vehicle systems specifications. A control strategy has been developed and implemented for this decision model and torque distribution control algorithm to achieve fuel economy optimization targets. A simulation model was setup for an exemplary target vehicle and WLTC cycle was run to validate the strategy. The simulation yield a near 37% improvement compared with similar 4WD vehicles equipped with conventional powertrain-2.0L TGDI and 6-speed AT.
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Experimental Investigation on the Impact of Engine Oil on RTV Silicone

Saginaw Valley State University-John Herman, Kirk Donaldson
  • Technical Paper
  • 2020-01-5002
Published 2020-01-17 by SAE International in United States
Silicone-based RTV sealants see widespread use in the automotive industry. In the uncured state, RTV silicone has the consistency of thick toothpaste and can be easily applied to form an effective seal. However, a significant amount of anecdotal evidence suggests issues exist with RTV’s ability to maintain a satisfactory seal in some long-term engine sealing applications. ASTM D7216 is used to evaluate the effects of different oil blends on a set of standard molded reference samples after submersion in an elevated temperature oil bath. The evaluated material properties are hardness, percent volume change, tensile strength, and ultimate elongation. A library of such results is readily available through Savant Laboratories of Midland, Michigan. Given RTV’s widespread use, surprisingly no such library of information exists concerning an engine oil’s effects on different RTVs. Due to difficulties in obtaining the reference oil, a commercially available engine oil was selected as a reference and RTV specimens were evaluated against the ASTM D7216 reference silicone (VMQ) for comparison. Both the hardness of the RTV and VMQ decreased by ~30%, though…
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Enhancement of Design for Manufacturing and Assembly Guidelines for Effective Application in Aerospace Part and Process Design

GITAM School of Technology-Mani Rathinam Rajamani, Eshwaraiah Punna
  • Technical Paper
  • 2020-01-6001
Published 2020-01-16 by SAE International in United States
An aircraft’s detail part and assembly product design and development phase contribute to about three-fourths of the total cost spent in its entire product life cycle and determine the fate of the aircraft’s life as a whole. Each aerospace design organization presently has developed their own set of design rules, focusing on improving product design capability by enhancing the determined “Design for X” factor, with the focus on continual optimization and improvements. However there is huge variation among these design principles due to the nonstandardization of these design guidelines. To meet this gap, the use of Design for Manufacturing and Assembly (DFMA®) principles applicable for aerospace has to be developed. DFMA®) principles have been proven effective as guidelines to designers and manufacturing engineers in various discrete manufacturing and process industries. The use of DFMA® principles have resulted in proactively simplifying designs with reduced product costs and improved efficiencies in product design. Aerospace Original Equipment Manufacturer (OEM) industries are highly oligopolistic in nature, and their designs are widely reliant on the specific intellectual knowledge gained by…
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Energy Release Characteristics inside a Spark-Ignition Engine with a Bowl-in-Piston Geometry

West Virginia University-Jinlong Liu, Cosmin Emil Dumitrescu
  • Technical Paper
  • 2020-01-5003
Published 2020-01-16 by SAE International in United States
The conversion of compression ignition (CI) internal combustion engines to spark-ignition (SI) operation by adding a spark plug to ignite the mixture and fumigating the fuel inside the intake manifold can increase the use of alternative gaseous fuels (e.g., natural gas) in heavy-duty applications. This study proposed a novel, less-complex methodology based on the inflection points in the apparent rate of heat release (ROHR) that can identify and separate the fast-burning stage inside the piston bowl from the slower combustion stage inside the squish region (a characteristic of premixed combustion inside a diesel geometry). A single-cylinder 2L CI research engine converted to natural gas SI operation provided the experimental data needed to evaluate the methodology, at several spark timings, equivalence ratios, and engine speeds. The results indicated that the end of the bulk combustion traditionally defined as the location of 90% energy release was not greatly affected by the change in operating conditions. Moreover, the actual duration of the rapid-burning stage was 60-80% shorter than the crank angle interval between 10% and 90% energy release.…
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