This study presents computational analyses of coaxial rotor hub flows and validation against experimental data obtained from the fifth Rotor Hub Flow Prediction Workshop. Experiments were conducted in a 12-inch diameter water tunnel at Pennsylvania State Applied Research Laboratory, employing tomographic particle-image velocimetry (Tomo-PIV) and precise hub drag measurements. Three CFD codes (UMD Mercury, CREATETM-AV Helios, and OVERFLOW) utilizing hybrid Reynolds-Averaged Navier-Stokes (RANS) / Large Eddy Simulation (LES) modeling based on Spalart–Allmaras turbulence model, were applied to replicate and analyze hub flows. Counter-rotating coaxial rotor hubs under free-air condition was simulated as the simplest case and the hub drags are compared between the three CFD codes. The full water tunnel configuration, consisting of two hubs, a fairing, and shafts, was also simulated and compared to experimental results, with a focus on hub drag, wake velocity fields, and turbulence

Jung, Yong Su, Baeder, James, Premaratne, Pavithra, Jain, Rohit, Deore, Neal, Coder, James, Schmitz, Sven, Gosin, Samuel

Development of Higher Clarity Injection Molded Windscreen for Motorcycles

2024-32-00404/18/2025

The windscreen is one of the key elements to enhance passenger comfort of touring motorcycle. The clarity through the windscreen should not discomfort the rider. The discomfort we discuss here mainly refers to three factors: the “distortion,” the “blur,” and the “transparency.” Introduced in this paper is the technical measures to achieve sufficient clarity by the injection molding method. Firstly, with respect to the “distortion,” we determined the main cause was local unevenness of plate thickness. As the uneven thickness were related to the accuracy of the die, we clarified the tolerable zone and carried out higher precision machining of the die to satisfy the requirements. Regarding the “blur,” we analyzed the refractive power of the windscreen and found the main cause of blur is the microscopic roughness on the surface. As the microscopic roughness were attributable to the die surface, we clarified the tolerable zone and established the polishing conditions satisfactory for the

Yamada, Atsushi, Endo, Sakae

SAE TOMORROW TODAY: Launching Human Space Travel with a Luxury Balloon

134981/23/2025

Imagine a six-hour journey to outer space that includes a world-class meal, cocktail service, Wi-Fi, and unprecedented views of Earth. This experience could soon become reality. Space Perspective, the world's first carbon-neutral spaceflight experience company, is commercializing space travel with Spaceship Neptune, a pressurized capsule propelled by a giant SpaceBalloon(TM). The experience is designed to be gentle and accessible with no rockets, weightlessness, heavy g-forces, or training required. Alongside world-class meal and cocktail service, space travelers will also enjoy views through the largest windows ever flown to space, Wi-Fi, and a proper restroom. To learn more, we sat down with Taber MacCallum, Founder and Chief Technology Officer, Space Perspective, to discuss the technical development of the SpaceBalloon(TM) and how the company is unlocking the market for space travel in a new and innovative way. We'd love to hear from you. Share your comments, questions and ideas for

Hineman, Marcie

Computational Analysis of Behavior and Structures of Coaxial Rotor Hub and Sail Fairing Wake

F-0080-2024-1312

5/7/2024

A computational study is conducted on a coaxial rotor hub and sail fairing configuration to analyze hub surface forces and the characteristics of its downstream wake. The flow conditions and grids are based on experimental tests performed at the Penn State Applied Research Lab (ARL) Water Tunnel at a baseline Reynolds number. Grid development for the rotor hubs and sail fairing is done using Pointwise v18.04R1 and Chimera Grid Tools (version 2.2). Simulations are performed using NASA's OVERFLOW2.4b Reynolds Averaged Navier-Stokes solver. The drag forces on the rotor hubs are computed and compared to standalone drag data to analyze the effects of interactional aerodynamics. Flow features, frequency content and Reynolds stresses of the wake are analyzed. Frequency content and Reynolds stresses show clear spatial bias. The anisotropy of the Reynolds stresses is computed and used to determine the character of the wake turbulence.

Deore, Neal, Coder, James

Aircraft Cockpit Window Improvements Enabled by High-Strength Tempered Glass

01-17-02-0012

1/25/2024

This research was initiated with the goal of developing a significantly stronger aircraft transparency design that would reduce transparency failures from bird strikes. The objective of this research is to demonstrate the fact that incorporating high-strength tempered glass into cockpit window constructions for commercial aircraft can produce enhanced safety protection from bird strikes and weight savings. Thermal glass tempering technology was developed that advances the state of the art for high-strength tempered glass, producing 28 to 36% higher tempered strength.As part of this research, glass probability of failure prediction methodology was introduced for determining the performance of transparencies from simulated bird impact loading. Data used in the failure calculation include the total performance strength of highly tempered glass derived from the basic strength of the glass, the temper level, the time duration of the load, and the area under load.A high-strength transparency

Lampman, DeWitt

Achieving New Pass-By Noise Regulatory Norms R51.3 (Method B) - An Analysis of Acceleration and Noise Source Contribution

2024-26-01991/16/2024

Worldwide automotive sector regulatory norms have changed and become more stringent and complex to control environmental noise and air pollution. To continue this trend, the Indian Ministry of Road Transport is going to impose new vehicle exterior pass-by noise regulatory norms R51.3 (Method B) in the upcoming year to control urban area noise pollution. This paper studies the synthesis of M1 category vehicle driving acceleration, dominant noise source, and frequency contribution in exterior PBN level. A vehicle acceleration analysis study was carried out to achieve an optimized PBN level based on the vehicle’s PMR ratio, reference, and measured test acceleration data. Based on the analysis, the test gear strategy and acceleration were changed to achieve a lower PBN level. Improved engine calibration resulted in a 20% increment of ith gear acceleration. This increased acceleration surpassed the upper limit of the reference acceleration range; hence, the vehicle was tested in a

kalsule cEng., Shrikant Balasaheb, Titave, Uttam, Patil, Jitendra, Jadhav, Kamalakar, Naidu, Sudhakara

Thermal Management of An Automotive Headlamp

2024-26-02861/16/2024

These days, the use of virtual simulations through Computation Fluid Dynamics (CFD) methodology is increasing exponentially during the development phase of an automotive headlamp. Thereupon, the automotive industries are becoming competent enough to build an ingenious and creative design with optimal performance within the coherent time. Considerable amount of heat is generated inside the headlamp when it is switched on for a longer time. Hence it becomes vital to reduce the risks if any during the development phase by providing an adequate thermal management strategy within the headlamp. The present study conducted an experimental analysis on an automotive headlamp to determine its thermal characteristics and behavior. Numerical analysis was also performed to determine the airflow and temperature distributions within a headlamp. This study also focuses on finding the main hotspot regions over the headlamp through virtual simulations. The methodology shows a consensus with the

Kolhe, Shailesh Madhukar

Design methodology for avoiding condensation in automotive head lamps

2024-26-00831/16/2024

One of the important aspect to consider at the design stage is the condensation of water vapor inside the lighting system, under particular weather conditions of temperature and humidity, which may compromise the device functionality. Condensation of water vapor is an issue affecting functional and aesthetics of Head Lamp. The current paper analyses the process of water vapor condensation inside an automotive LED head lamp. This paper also discusses the design methodology to avoid condensation under particular conditions. Design methodology includes design considerations for better air movement for heat management, material selection, ease of moisture exchange, breather or vent selection, placement. Additionally, this paper would also discuss about effective use of simulations tools, test methods and assembly process guidelines to avoid impact due to condensation. This paper would consist of one example with application of above methodology, its test and field results.

RANE, SANDEEP BALU, Pawar, Nishant

Determination of the structural member life cycle without undergoing complete testing using CAE input for an improved design after failure correlation

2024-26-03331/16/2024

This case study involves the failure of the wheel arch of a medium duty commercial vehicle. The wheel arch is an important vehicle trim aggregate from both the regulatory perspective (spray suppression) as well as from the aesthetics of the truck. But, the durability of this part is affected by the vehicle architecture, vehicle load capacity as well as the operating conditions. This is more critical due to the nature of the overhang experienced by the mounting bracket assemblies that hold these wheel arches/mud flaps. This generally consist of tubular and sheet metal welded structures bolted on to the main chassis long members. Some premature failures were observed in a legacy vehicle, where very little details of the complete vehicle digital simulation and testing performance were readily available. This paper deals with the a) identification of the root cause of the failure b) simulation of the root cause in CAE c) improvement in design d) CAE evaluation of improved design e

Venkatesh, Srinivasa

Physical Testing and Evaluation of methodology for Windscreen wiping zones and vision zones of vehicle category other than M1.

2024-26-03661/16/2024

The windscreen wiping system is mandatory requirement for automotive vehicle as per Central motor vehicle rules. The main scope of the standard is to ensure vision zones to be wiped by wiping system to ensure maximum field of vision to the driver. The evaluation of vision zones as per IS 15802:2008 is generally determined by virtual simulation by OEMs. The Limitation of virtual simulation is actual tolerances in vehicle due to seat fitment, ergonomic dimensions and seat cushioning effect are not taken into consideration very well off. The testing methodology described in the paper is an in-house developed test method. 3D H-point machine( SAE J826) and a laser based machine Theodolite is used to develop various vision zones on an actual vehicle windscreen as per technical data. These zones are later compared with wiped area to evaluate field of vision. The standard is applicable to vehicle other than M1 category. Critical vehicle parameters such as SgRP( seating reference point) , seat

Joshi, Amol

Enhanced Development Process for UPDs – Digital Approach

2024-26-02391/16/2024

Underrun Protections devices (UPDs) are specially designed barriers fitted to the front, side, or rear of heavy trucks. In case of accidents, these devices prevent small vehicles such as bikes and passenger cars going underneath and thus minimizing the severity of such accident. Design and strength of UPD is such as to absorb the impact energy and minimise deflection to avoid the under run. Compliance to UPD safety regulations provides stringent requirements in terms of device design, dimensions, and its behaviour under loading. Since accuracy of Computer Aided Engineering (CAE) predictions have improved, use of numerical tools like Finite element method (FEM) are extensively used for design, development, optimisation, and performance verification with respect to regulatory requirements. For improved accuracy of prediction of results through FEA, correct representation of sub-systems is very important. One such sub-system in UPDs is bolted connections, which require accurate methods to

Ugale, Dinesh, D, Dileep Kumar, Mohod, Pravin, Khaleelullah, Abdul, Bandru, Shreenu

Application of Color Light-Emitting Diodes in Automotive Exterior Lighting

2024-01-50031/15/2024

Trends in automotive lighting are moving toward vehicle exterior lights, which will communicate with drivers and surroundings. The small size, lower power consumption, high efficiency, and substantially long life make LEDs a leading light source in automotive lighting applications. Losses in optical power for InGaN-based LEDs can be reduced up to 45% compared to AlGaInP, and phosphor-converted color LEDs can contribute to stable light output over the lifetime. Color LEDs will fulfill different requirements such as uniformity in color and luminance. Additionally, the mixing of different colors with white will underline the exterior features and aesthetic design of vehicles.

Janeva Azdejkovic, Mersida, Denis, Xavier, Matsuyama, Yuji, Miyairi, Hiroshi

Categorizing Simulation Models Using Convolutional Neural Networks

2023-01-12176/26/2023

Engineers come across frequent problems solved using artificial intelligence. Tasks of neural networks are often considered solving problems in such an intelligent manner. Whether as an optimization problem or development tool, neural networks help engineers and create a more efficient approach. Furthermore, information is stored in a unique data structure, during a project cycle. Engineers often face a time-consuming search to get an understanding of the project itself. This process of understanding the data needs to be repeated by every engineer, if not further documented. E.g. searching for a past project with similar parameters can be a big task, regarding huge databases. Worker fluctuation can increase the cost of this process as well. To address this issue, neural networks make a significant contribution. The main aspect of this paper is to add meta data to the core files of the project. With such labels it is possible to get access to the content of the model files of an engine

Grbavac, Andrija, Angerbauer, Martin, Grill, Michael, Kulzer, André

Computational Analysis of Coaxial Rotor Hub and Sail Fairing Wake

F-0079-2023-17994

5/16/2023

ABSTRACT

Deore, Neal, Mobley, Forrest, Coder, James

Excavator exterior noise contribution analysis using angle-based operational acoustic load synthesis.

2025-01-00625/5/2023

Since earth moving machines (EMM) are subject to exterior noise (EN) regulations, OEMs need to develop mitigation solutions from an early design stage. It is challenging to predict solution effectiveness at early design stage. Excavators are distinct compared to other EMM as their upper frame rotate while keeping lower frame fixed. ISO 6395(2) or EC/2000/14(1) require EMMs to follow specific operating maneuvers where noise sources change their position, directivity, and speed along the operating cycle. These conditions pose challenges in performing noise contribution analysis as a function of angular position and operating condition. Authors successfully demonstrated Acoustic source quantification and contribution analysis for linearly moving EMMs. However, excavator pose data processing challenges due to angular motion. This work demonstrates the use of frequency domain ASQ for operational acoustic source quantification and use of frequency domain virtual prototype sub structuring

Vesikar, Prasad Balkrishna, Haynes, Timothy, Aquino Arriaga, Adrian Antonio, Drabison II, John, Chaduvula, Prasanna

Underbody contribution simulation for vehicle wind-noise.

2025-01-00265/5/2023

Wind noise is one of the largest sources to the interior noise of modern electric and hybrid vehicles. This noise is encountered when driving on roads and freeways from medium speed and generate considerable fatigue for passengers on long journeys. Aero-acoustic noise is the result of turbulent and acoustic pressure fluctuations created within the flow. They are transmitted to the passenger compartment via the vibro-acoustic excitation of vehicle surfaces and underbody cavities. Generally, this is the dominant flow-induced source at low frequencies. The transmission mechanism through the vehicle floor and underbody is a complex phenomenon as the paths to the cavity can be both airborne and structure-borne. This study is focused on the floor contribution to wind noise of different type of vehicles (SUV and Sport car), whose underbody structure are largely different. Aero-Vibro-acoustic simulations are performed to clarify the transmission mechanism of the underbody wind noise and

Mordillat, Philippe, Zerrad, Mehdi, Errico, Fabrizio

Pass-by noise comparison of two test facilities with vehicles operating in electric mode

2025-01-00055/5/2023

Outdoor test facilities for light vehicle exterior noise regulatory measurement need to have surfaces certified to meet ISO 10844. A recent study considered plug-in-hybrid vehicles operating purely in electric mode to compare results at two facilities, one in Japan and in the U.S. This emphasizes the pavement contribution. Overall results are generally similar, with a few differences which are discussed.

Sorenson, Steve, Shao, Guangxin

2025-01-00255/5/2023

Sound source identification based on beamforming is widely used today as a spatial sound field visualization technology in wind tunnel experiments for vehicle development. However, the conventional beamforming technique has its inherent limitations. To improve the performance, three deconvolution methods CLEAN, CLEAN-SC and DAMAS were investigated. These algorithms were applied for the wind noise sources identification on a production car. After analysis of vehicle exterior wind noise sources distribution, to study the energetic contribution of identified exterior noise sources to interior noise, correlation analysis between them were conducted. The results show that, the algorithm CLEAN-SC based on spatial source coherence shows the outstanding capability to remove the sidelobes for the uncorrelated wind noise sources, while CLEAN and DAMAS which based on point spread function have definite limitations. In the application aspect, the main noise source outside vehicle is from the

He, Yinzhi, Shen, Henghao, Wu, Yu, Zhang, Lijun, Yang, Zhigang

Study on the Aspiration Effect of Glassrun Seal System Based on Time-Varying Pressure Difference Between Vehicle Exterior and Interior

2025-01-00305/5/2023

When the vehicle is driven at high speed, there exist very complex flow and vortex shedding phenomenon at the side window area with intense pressure fluctuations. When the dynamic pressure difference between vehicle exterior and interior is large enough, the side window sealing system is prone to poor sealing and generates leakage noise, which can severely affect vehicle interior acoustic comfort. To study the dynamic aspiration mechanism of the sealing system, a nonlinear finite element model of the glassrun seal was established to simulate the quasi-static installation deformation process of the sealing strip, and to obtain the deformed geometric shape and residual stress. Then, the exterior flow field of the glassrun sealing area of a simplified vehicle model was calculated with CFD simulation to obtain the hydrodynamic pressure excitation acting on the outer surface of the sealing strip at different vehicle speeds, and the results were subsequently validated through wind tunnel

Li, Hanqi, He, Yinzhi, Zhang, Yongfeng, Zhang, Lijun, Yu, Wuzhou, Jiang, Zaixiu

An Aerodynamic Equation of State—Part I: Introduction and Aerospace Applications - QA Test Tatsiana

01-17-01-0001

4/19/2023

Abstract In subsonic aircraft design, the aerodynamic performance of aircraft is compared meaningfully at a system level by evaluating their range and endurance, but cannot do so at an aerodynamic level when using lift and drag coefficients, CL and CD , as these often result in misleading results for different wing reference areas. This Part I of the article (i) illustrates these shortcomings, (ii) introduces a dimensionless number quantifying the induced drag of aircraft, and (iii) proposes an aerodynamic equation of state for lift, drag, and induced drag and applies it to evaluate the aerodynamics of the canard aircraft, the dual rotors of the hovering Ingenuity Mars helicopter, and the composite lifting system (wing plus cylinders in Magnus effect) of a YOV-10 Bronco. Part II of this article applies this aerodynamic equation of state to the flapping flight of hovering and forward-flying insects. Part III applies the aerodynamic equation of state to some well-trodden cases in fluid

Burgers, Phillip