This paper introduces a comprehensive model, specifically developed to inherently capture interactional effects. Due to the high computational cost associated with the large analysis matrix including variations in angle of attack, angle of sideslip, velocity, and weight, a surrogate model is used in creating aerodynamic databases. This database, which reflects interactional effects under a wide range of flight speed, angle of attack, angle of sideslip, and weight configuration, is integrated into a rotorcraft analysis tool. Simulations are performed, and results are compared against flight test data for the T625 Gökbey, covering low-speed, high-speed, rightward and climb conditions. The results highlight the impact of interactional aerodynamics on flight characteristics and load predictions. Overall, the study emphasizes the importance of including interactional effects to ensure accurate and reliable rotorcraft design in the early design stages without requiring flight test data.

Erkan, Mehmet Ali, Madenci, Mustafa Alperen, Güngör, Osman, Şenipek, Murat, Ezertaş, Ahmet Alper

Nonlinear Joint Dynamic Estimator of Sideslip Angle and Tire-Road Peak Adhesion Coefficient Based on Improved Brush Tire Model

2024-01-703312/13/2024

The sideslip angle and tire-road peak adhesion coefficient (TRPAC) are crucial parameters for intelligent active safety systems in automobiles. The accuracy and real-time estimation of these parameters significantly affect control effectiveness. And there is a strong coupling between the two parameters, which brings great challenges to the joint estimation. This paper proposes a nonlinear dynamic estimator that pre-estimates tire lateral force to achieve synchronous estimation of sideslip angle and TRPAC. Additionally, to cope with sudden changes in road adhesion condition, a TRPAC preliminary estimation optimization algorithm is introduced. Moreover, an adaptive gain adjustment algorithm for the sideslip angle estimator is implemented to address large lateral excitation conditions. Simulation results on various road surfaces and under various lateral excitation conditions demonstrate that the proposed joint estimator enables accurate and rapid estimation of sideslip angle and TRPAC.

Zhao, Wenrui, Leng, Bo, Han, Yinfeng, Yu, Zhuoping, Xiong, Lu

Aerodynamic investigation of a helicopter rotor hovering in the vicinity of a building

F-0074-2018-12690

5/7/2024

ABSTRACT At the end of 2014, the Group for Aeronautical Research and Technology in EURope (GARTEUR) launched an action group (named AG22) in order to address both experimentally and numerically the issue of rotor wake interacting with obstacles. Within this group, several different experiments were set up and the results were provided to all the partners in order to compare and improve their numerical methods aimed at capturing interaction effects. In the present paper, we numerically investigate the experimental database provided by Politecnico di Milano (Polimi). A low fidelity method based on free wake approach and also CFD computations with different level of modeling are compared to experimental data. It shows that free wake approach is perfectly suitable to predict interaction effects on the rotor loads as long as there is no wake re-ingestion by the rotor. In other cases, the use of CFD is mandatory. However, computational cost can greatly be reduced using some approximation (no

Boisard, Ronan

Design of a Model-Based Optimal Multivariable Control for the Individual Wheel Slip of a Two-Track Vehicle

2023-01-12196/26/2023

The concept of autonomous driving has become increasingly relevant. This is why innovative drive concepts for motor vehicles need to be developed. Therefore, a model-based optimal multivariable control for the wheel slip is presented in this paper. This allows to specify the slip, and thus the tire force, individually for each wheel. The plant model consists of a planar and stiff multibody two-track model of a vehicle, a complex tire model as well as a simple air resistance and motor model. In addition, the contact forces of the individual wheels are calculated dynamically. A special feature of the multibody model is that the vehicle's position variables are defined by integrating the velocity variables. The linearized model derived from the nonlinear model is used to design a linear optimal static state space controller (LQR) including reference and disturbance feedforward. The contact point velocities of the tires are defined as the controlled variables, since they are proportional

Irmer, Marcus, Rosenthal, Robert, Nüßgen, Alexander, Degen, René, Thomas PhD, Karin, Ruschitzka PhD, Margot

Flight Test Measurement of Quadrotor Performance at Varying Sideslip Angles

F-0078-2022-17642

5/10/2022

ABSTRACT

McCrink, Matthew, Seth, Dhuree, Herz, Sage

Controller design for path tracking of autonomous vehicle incorporating four-wheel steering system

2022-01-03463/29/2022

This research aims to model and assess autonomous vehicle controller while including a four-wheel steering and longitudinal speed control. Such a modeling process simulates human driver behavior with consideration of real vehicle dynamics’ characteristics during standard maneuvers. However, a four-wheel steering control improves vehicle stability and maneuverability as well. A two-degree of freedom bicycle model, lateral deviation and yaw angle, is constructed to describe vehicle dynamics’ behavior. Moreover, a comprehensive traction model is implemented which includes an engine, automatic transmission, and non-linear magic formula tire model for simulation of vehicle longitudinal dynamics. A combination of PID longitudinal controller and fuzzy lateral controller are implemented simultaneously to track the desired vehicle path while minimizing lateral deviation and yaw angle errors. Then, A LQR based rear steering controller is introduced to represent a performance improvement over

Gafar, Ibrahim, Oraby, Walid, Aly, Mahmoud Atef

Event-triggered Adaptive Robust Control for Lateral Stability of Steer-by-wire Vehicles with Abrupt Nonlinear Faults

2022-01-11123/29/2022

Owing to the fact that autonomous vehicles equipped with active front steering (AFS) have the features of time-varying, uncertainties, high rate of fault and high burden on the in-vehicle networks, this article studies the adaptive robust control problem for improving steer-by-wire (SBW) vehicles lateral stability in the presence of abrupt nonlinear faults. Firstly, a robust H∞ controller, as an upper-level controller, is designed to obtain the corrected steering angle for driving both the yaw rate and the sideslip angle to achieve their desired values. Takagi-Sugeno (T-S) fuzzy modeling approach which has shown the extraordinary ability in coping with the issue of nonlinear is applied to deal with the challenge of the changing longitudinal velocity. The output of upper controller can be calculated by parallel-distribute-compensation (PDC) scheme. Then, an event triggered adaptive fault tolerant lower controller is proposed to track the desired front wheel steering angle offered by the

zheng, gong, Xie, Zhengchao, Zhao, Jing

Hierarchical Vehicle Stability Control Strategy Based on Unscented Kalman Filter Estimation

2022-01-03433/29/2022

High-speed vehicle is prone to instability under bad road conditions, causing many safety accidents such as tail-flicking and overturning. Stability control could assist vehicle to drive safely and stably by adjusting the additional yaw moment. However, most of the existing stability control strategies directly invoke the information of the sideslip angle of the centroid that is difficult to obtain on the vehicle, and carry out complex controller design, which deviates from the actual application. In order to achieve a complete set of stability control architecture oriented to practical applications, this paper designs a hierarchical vehicle stability control strategy based on differential braking and state estimation technology. Firstly, a model oriented to state estimation and controller design is built according to the vehicle's motion state; Secondly, the sideslip angle of the centroid is accurately estimated through the unscented Kalman filter algorithm; Subsequently, the sliding

Zhang, Jian, Jiang, Hongwei, Li, Linrun, Liu, Qiuzheng, Wang, Yu, Liu, Jinbo, Gao, Yuan, Chen, Zhicheng

Speed Limiter Using Disturbance Observer

2021-01-01024/6/2021

This paper suggests disturbance observer which improves performance of speed limit assist control. The nonlinear disturbance observer was designed so that disturbance caused by parameter and load uncertainties is able to be estimated exponentially. With the contribution of the observer, feed-forward and integral controllers can be omitted while improving steady-state error elimination and overshoot reduction. The acceleration observer is also designed to reduce the effect of wheel slip and changing slope. The performance of the controllers has been verified not only on flat roads, but also on wave road and rapidly changing ramps.

Son, Huiun, Jo, Kyuhwan, Kim, Sangjoon, Cho, Jinkyeom, Jeon, Sungbae

Slip Speed and Drive Torque Planning of Multivariable Controller for an Electrified Vehicle with Dual Clutch Transmission

2020-01-22439/15/2020

Demand for electrified vehicles is increasing due to increased environmental pollution regulations and interest in highly efficient vehicles. According to these demands, research on electrified vehicles equipped with Dual Clutch Transmission (DCT) has been actively conducted for the purpose of improving energy efficiency of electrified powertrain, maximizing acceleration performance, and increasing maximum speed. However, since DCT requires clutch to clutch shifting, it is difficult to control drive torque and slip speed using two clutch actuators and a power source input. In order to solve this, a study on a multivariable shift controller has been conducted. However, this study chose a heuristic planning method to control the two outputs. However, since the slip speed and drive torque are coupled, it is necessary to tune the reference for every shift scenario, as well as create unnecessary control inputs or degrade shift control performance. Therefore, this study proposes a reference

Kim, Dong-Hyun, Choi, Seibum

Injectable Gel Helps Heart Muscle Regenerate

TBMG-368625/1/2020

In mammals, including humans, the cells that contract the heart muscle and enable it to beat do not regenerate after injury. After a heart attack, there is a dramatic loss of these heart muscle cells, and those that survive cannot effectively replicate. With fewer of these contractile cells, known as cardiomyocytes, the heart pumps less blood with each beat, leading to the increased mortality associated with heart disease.

New Control Method of Four-Wheel Independent Driving Electric Vehicles for Anti-Slip Purposes

2020-01-14204/14/2020

The performance of electric vehicles could be enhanced by more flexible drivetrain configurations combined with advanced control method. Based on the four wheel independent driving and front and rear axle modular steering configuration, which was proposed by our research group last year, the problem of slippery under close-to-limit conditions are further discussed and simulated. A new torque vectoring method based on obtainable parameters and variables in real driving situations is introduced to reduce the sideslip when turning on low friction coefficient surfaces or with high speed. This method is developed from a comprehensive index, which reflects the stability and maneuverability, by adding additional torques when stability could not be compensated enough by basic torque vectoring. Besides, an improvement of adding a simu-Torsen differential mechanism is made to the model of the vehicle, which enables another control method with the same purpose as before. This method is combined

Liu, Chen, Zheng, Gangtie

Electronic Differential Control of Rear-Wheel Independent-Drive Electric Vehicle

10-04-01-000412/2/2019

To track desired slip ratios and desired longitudinal speeds at the centers of driving wheels in the curve, this article proposes a hierarchical structured electronic differential control (EDC) of rear-wheel independent-drive electric vehicle (EV). In the high-level control, a fuzzy algorithm-based coefficient is computed according to the driver’s emotional intention of acceleration. The fuzzy algorithm-based coefficient is used to correct the desired driving torque of vehicle transmitting to the medium-level control. In the medium-level control, an optimization algorithm is developed to allocate the desired torques with requirement of as much accurate yaw moment as possible by the desired driving torque of the vehicle and yaw moment. And the desired longitudinal speeds at the centers of the rear left and right wheels are corrected twice, respectively, by Ackermann steering principle, considering the slip angle of the wheel and yaw moment. Based on the desired torques and desired

He, Ren, Yun, Hang

Algorithm Gives Robots a Faster Grasp

TBMG-3561512/1/2019

A robot that's sorting through a bin of objects and attempting to get a good grasp on one of them is performing a computationally taxing maneuver. Before even attempting the move, it must calculate a litany of properties and probabilities such as the friction and geometry of the table, the pen, and its two fingers, and how various combinations of these properties interact mechanically based on fundamental laws of physics.

A Novel Heating-Coating Hybrid Strategy for Wind Turbine Icing Mitigation

2019-01-20296/10/2019

The electro-thermal method is most commonly used for wind turbine anti-/de-icing. The upmost drawback of such systems is the high power consumption. In the present study, we proposed to use a durable slippery liquid-infused porous surface (SLIPS) to effectively reduce the power requirement of the heating element during the anti-/de-icing process. The explorative study was conducted in the Icing Research Tunnel at Iowa State University (ISU-IRT) with a DU91-W2-250 wind turbine blade model exposed under severe icing conditions. During the experiments, while a high-speed imaging system was used to record the dynamic ice accretion process, an infrared (IR) thermal imaging system was also utilized to achieve the simultaneous surface temperature measurements over the test model. In comparison to the traditional electrical heating strategies to brutally heat massive area of entire turbine blades, a novel heating-coating hybrid strategy, i.e., combining a leading-edge (LE) heating element to

Gao, Linyue, Ma, Liqun, Liu, Yang, Hu, Hui

An Experimental Investigation of a Wind-Driven Water Droplet over the Slippery Liquid Infused Porous Surface

2019-01-19516/10/2019

The promising anti-icing performance of the slippery liquid infused porous surface (SLIPS) has been recently demonstrated for various engineering applications. The runback icing for aircraft and wind turbines could be effectively mitigated considering the timely removal of water droplet by the wind shearing force due to the low adhesion on the SLIPS. In this study, the flow field both inside and around the wind-driven droplet over the SLIPS was experimentally investigated by using Particle Image Velocimetry (PIV) technique. Previous studies majorly focus on the internal flow pattern before the droplet incipient motion. In this study, the flow field inside a moving droplet was firstly investigated. As a result of the low surface adhesion of the SLIPS, droplet oscillations were eliminated and the droplet internal flow field could be corrected from the optical distortion. Besides the discussion on the wind speed, the droplet viscosity was also studied by varying the water concentration of

Ma, Liqun, Hu, Hui

An Experimental Study to Evaluate the Droplet Impinging Erosion Characteristics of an Icephobic, Elastic Soft Surface

2019-01-19976/10/2019

Elastic soft material/surface, such as Polydimethylsiloxane (PDMS), is a perspective, useful and low-cost hydrophobic and icephobic coating. While it has been reported to have good mechanical durability, its erosion durability under the high impacting of water droplets pertinent to aircraft inflight icing phenomena has not been explored. In this study, the droplet imping erosion characteristics of an icephobic PDMS surface/material is evaluated systematically upon the dynamic impinging of water droplets at different impact velocities (~ up to 75m/s), in comparison with other state-of-the-art icephobic materials/surfaces, such as superhydrophobic surface (SHS) and slippery liquid-infused porous surface (SLIPS). Surprisingly, the contact angle (CA) of the elastic PDMS is shown to have an over 20° increase (from 105° to 128°), which represents better hydrophobicity, after the erosion test which is mainly contributed to the higher roughness of the eroded PDMS surface. As for the

Ma, Liqun, Zhang, Zichen, Liu, Yang, Hu, Hui

Event Data Recorder Performance during High Speed Yaw Testing Subsequent to a Simulated Tire Tread Separation Event

2019-01-06344/2/2019

This paper presents event data from the Sensing and Diagnostic Module (SDM) of a 2004 Chevrolet Malibu during high speed yaw testing. Yaw tests were performed using tires that were intact and tires that had the tread removed. The tires that had the tread removed were placed at various wheel positions on the vehicle (e.g. leading side - front, leading side -rear, trailing side - rear). This testing simulates the loss of control phase subsequent to a tread separation. Speeds up to 117 km/h (72.9 mph) were achieved. A simple electro-mechanical device was incorporated to the dynamic testing to simulate a low-severity non-deployment event that triggered the recording of pre-crash data by the SDM. The SDM data from the tests was imaged and compared to reference data from vehicle-mounted instrumentation recording wheel speed, steering angle, measured vehicle sideslip angle and GPS calculated over the ground speed. This paper examines the dynamic effect of high sideslip angles and changes to

Bortles, William, Koch, Daniel, Beauchamp, Gray, Pentecost, David, Rayburn, George, Hostetler, Ryan

Model-Based Approaches in Developing an Advanced Aftertreatment System: An Overview

2019-01-00261/15/2019

Cummins has recently launched next-generation aftertreatment technology, the Single ModuleTM aftertreatment system, for medium-duty and heavy-duty engines used in on-highway and off-highway applications. Besides meeting EPA 2010+ and Euro VI regulations, the Single ModuleTM aftertreatment system offers 60% volume and 40% weight reductions compared to current aftertreatment systems. In this work, we present model-based approaches that were systematically adopted in the design and development of the Cummins Single ModuleTM aftertreatment system. Particularly, a variety of analytical and experimental component-level and system-level validation tools have been used to optimize DOC, DPF, SCR/ASC, as well as the DEF decomposition device. The highlights of this work can be summarized as follows: a). internal dosing is more efficient than external dosing to control HC slip; High CPSI DOCs show better HC oxidation performance at high SV due to enhanced mass transfer; b). the adopted advanced

Su, Changsheng, Brault, Joseph, Munnannur, Achuth, Liu, Z. Gerald, Milloy, Sean, Harinath, Arvind, Dunnuck, David, Federle, Ken

Boundary Layer Dynamics and Sound Generation

2018-01-190010/5/2018

In recent years, characteristic structures in the boundary layer of high-load contacts such as brakes have been reported, which substantially influence the dynamics of the tribological contact. Usually, local assumptions concerning the friction behavior of these patches are used to reach global conclusions about the brake system. Several numerical methods (e.g. Cellular Automata) have been developed which employ such assumptions. The validation of these methods through measurement data tends to be laborious and costly. Sprag-Slip elements are friction elements that are exclusively subjected to static friction, never undergoing sliding friction. Implementing such elements on a mesoscopic scale, it is possible to generate global descriptions of macroscopic stick and slip friction phenomena. Locally, these Sprag-Slip elements are similar to the patch structures in the tribological boundary layer of brakes. The Sprag-Slip elements are suitable for describing the basic physics in the

Recke, Bastian, Ostermeyer, Georg

GPS Enabled Semi-Autonomous Robot

TBMG-289045/1/2018

The primary objective of this research is to integrate GPS and local sensory data to allow a robot to operate semi-autonomously outside of a laboratory environment. The Pioneer 3-AT, a robust platform capable of operating in the outdoors, is utilized in this project. The P3-AT has acoustic sensors that can calculate distances to obstacles and encoders that calculate how much each wheel has turned. In a laboratory environment, sensory and encoder information can be used to triangulate position or measure distance and direction traveled from a known starting point. Operating outdoors limits the effectiveness of both systems as the obstacles are not known and wheels can often slip and slide on different surfaces. This necessitates external data to determine the location of the robot. GPS was chosen to provide that data. GPS, acoustic, and encoder data were integrated within MATLAB and provided control signals to the robot.

Vehicle Sideslip Angle Estimation Considering the Tire Pneumatic Trail Variation

2018-01-05714/3/2018

Vehicle sideslip angle is significant for electronic stability control devices and hard to estimate due to the nonlinear and uncertain vehicle and tire dynamics. In this paper, based on the two track vehicle dynamic model considering the tire pneumatic trail variation, the vehicle sideslip angle estimation method was proposed. First, the extra steering angle of each wheel caused by kinematics and compliance characteristics of the steering system and suspension system was analyzed. The steering angle estimation method was designed. Since the pneumatic trail would vary with different tire slip angle, distances between the center of gravity (COG) and front&rear axle also change with the tire slip angle. Then, based on the dynamic pneumatic trail and estimated steering angle, we modified the traditional two track vehicle dynamic model using a brush tire model. This model matches the vehicle dynamics more accurately. In addition, we designed two extended Kalman filters (EKF) based on the

Xia, Xin, Xiong, Lu, Lin, Xuefeng, Yu, Zhuoping

A Computational and Experimental Investigation into the Effects of Debris on an Inverted Double Wing in Ground Effect

2018-01-07264/3/2018

Cars in several motor sports series, such as Formula 1, make use of multi-element front wings to provide downforce. These wings also provide onset flows to other surfaces that generate downforce. These elements are highly loaded to maximise their performance and are generally operating close to stall. Rubber debris, often known as marbles, created from the high slip experienced by the soft compound tyres can become lodged in the multiple elements of a front wing. This will lead to a reduction in the effectiveness of the wing over the course of a race. This work will study the effect of such debris, both experimentally and numerically, on an inverted double element wing in ground effect at representative Reynolds numbers. The wing was mounted at two different ride heights above a fixed false-floor in the Loughborough University wind tunnel and the effect of debris blockage modelled by closing sections of the gap between elements with tape. The reduction in downforce compared to the

Corfield, Emma, Hodgson, Graham, Garmory, Andrew

A Study on Front End Auxiliary Drive(FEAD) System of 48V Mild Hybrid Engine

2018-01-04144/3/2018

48V mild hybrid engine is one of major eco-friendly technology for global CO2 reduction policy. The 48V mild hybrid engine enables to operate torque boost, recuperation and ISG status by MHSG(Mild Hybrid Starter and Generator). The FEAD(Front End Auxiliary Drive) system is a very important role to transfer MHSG power to crankshaft at the mild hybrid engine. The conventional FEAD configuration is relatively simple because it transfers power from crankshaft to auxiliary drive components in one direction. But the FEAD configuration of 48V mild hybrid engine is not simple due to bidirectional power transmission between crankshaft and MHSG. For instance, in case of torque boost mode, the tight side of auxiliary belt is entry span of MHSG. On the contrary, the tight side of auxiliary belt is exit span of MHSG at recuperation mode. As a result, to continue auxiliary belt tension constantly is very difficult and important for 48V mild hybrid engine development because the change of belt

Yoon, Kibong, Hong, Jisoo, Shim, JaeYoung

Vehicle Sideslip Angle Estimation: A Review

2018-01-05694/3/2018

Vehicle sideslip angle estimation is of great importance to the vehicle stability control as it could not be measured directly by ordinary vehicle-mounted sensors. As a result, researchers worldwide have carried out comprehensive research in estimating the vehicle sideslip angle. First, as the attitude would affect the acceleration information measured by the IMU directly, different kinds of vehicle attitude estimation methods with multi-sensor fusion are presented. Then, the estimation algorithms of the vehicle sideslip angle are classified into the following three aspects: kinematic model based method, dynamic model based method, and fusion method. The characteristics of different estimation algorithms are also discussed. Finally, the conclusion and development trend of the sideslip angle estimation are prospected.

Liu, Wei, Xiong, Lu, Xia, Xin, Yu, Zhuoping

A Nonlinear Slip Ratio Observer Based on ISS Method for Electric Vehicles

2018-01-05574/3/2018

Knowledge of the tire slip ratio can greatly improve vehicle longitudinal stability and its dynamic performance. Most conventional slip ratio observers were mainly designed based on input of non-driven wheel speed and estimated vehicle speed. However, they are not applicable for electric vehicles (EVs) with four in-wheel motors. Also conventional methods on speed estimation via integration of accelerometer signals can often lead to large offset by long-time integral calculation. Further, model uncertainties, including steady state error and unmodeled dynamics, are considered as additive disturbances, and may affect the stability of the system with estimated state error. This paper proposes a novel slip ratio observer based on input-to-state stability (ISS) method for electric vehicles with four-wheel independent driving motors. Instead of estimating vehicle speed, the proposed method employs the estimated error of motor torque as the correction output by taking the advantage of

Ren, Bingtao, Deng, Weiwen, Chen, Hong, Wang, Jinsong

Discrete Surface Dynamics: Distributed Sprag Slip Elements in Brakes

2017-01-25319/17/2017

In recent years, characteristic structures in the boundary layer of high-load contacts such as brakes have been reported, which have an important impact on the dynamics of the tribological contact. Usually, local assumptions concerning the friction of these patches are used to reach global conclusions about the brake system. Several numerical methods (e.g. Cellular Automata) have been developed which make use of such assumptions. The validation of these methods through measured data tends to be laborious and costly. Sprag-Slip elements are friction elements which are typically considered to exclusively undergo static friction. Such elements have been sporadically utilized towards describing friction in brake applications. In this paper, many locally distributed Sprag-Slip elements are used to model the global dynamics of braking friction. The results show good agreement with the measured characteristics of brakes. This approach offers new possibilities for the description of global

Ostermeyer, Georg Peter, Recke, Bastian

Vehicle Stability Criterion Research Based on Phase Plane Method

2017-01-15603/28/2017

In this paper, a novel method is proposed to establish the vehicle yaw stability criterion based on the sideslip angle-yaw rate (β-r) phase plane method. First, nonlinear two degrees of freedom vehicle analysis model is established by adopting the Magic Formula of nonlinear tire model. Then, according to the model in the Matlab/Simulink environment, the β-r phase plane is gained. Emphatically, the effects of different driving conditions (front wheels steering angle, road adhesion coefficient and speed) on the stability boundaries of the phase plane are analyzed. Through a large number of simulation analysis, results show that there are two types of phase plane: curve stability region and diamond stability region, and the judgment method of the vehicle stability domain type under different driving conditions is solved. Finally, different conditions of stability boundary plane database look-up tables are set up, besides, the effects of different conditions on the stability boundary’s

Liu, Wei, Xiong, Lu, Leng, Bo, Meng, Haolan, Zhang, Renxie

A Hybrid Approach to Model the Temperature Effect in Tire Forces and Moments

2017-01-96763/14/2017

Tire is an integral part of any vehicle which provides contact between the vehicle and the surface on which it moves. Forces and moments generated at the tire-road interaction imparts stability and control of motion to the vehicle. These forces and moments are functions of many variables such as slip, slip angle, contact pressure, inflation pressure, coefficient of friction, temperature, etc. This paper deals with the effect of temperature on the lateral force, the longitudinal force and the self-aligning moment. The analysis is done at different tire surface temperatures such as 20°C, 40°C, and 60°C. Since the experimental set up with the mounted tire is complex and expensive, we use a hybrid approach in which we take the results from the experiments done by the researchers on a sample piece of tire rubber at various temperatures. Then, we do the steady state analysis in ABAQUS considering the variation of coefficient of friction, slip speed and the elastic modulus of rubber with

S, Bibin, Pandey, Ashok Kumar

A Droplet Size Investigation and Comparison Using a Novel Biomimetic Flash-Boiling Injector for AdBlue Injections

2016-01-221110/17/2016

Increased research is being driven by the automotive industry facing challenges, requiring to comply with both current and future emissions legislation, and to lower the fuel consumption. The reason for this legislation is to restrict the harmful pollution which every year causes 3.3 million premature deaths worldwide [1]. One factor that causes this pollution is NOx emissions. NOx emission legislation has been reduced from 8 g/kWh (Euro I) down to 0.4 g/kWh (Euro VI) and recently new legislation for ammonia slip which increase the challenge of exhaust aftertreatment with a SCR system. In order to achieve a good NOx conversion together with a low slip of ammonia, small droplets of Urea solution needs to be injected which can be rapidly evaporated and mixed into the flow of exhaust gases. In most of today's solutions this process is enhanced with flow restricting mixers or longer path lengths but if these can be removed and shortened the flow losses can be reduced, leading to higher

Larsson, Peter, Lennard, Will, Andersson, Oivind, Tunestal, Per

NOx-Conversion and Activation Temperature of a SCR-Catalyst Whilst Using a Novel Biomimetic Flash-Boiling AdBlue Injector on a LD Engine

2016-01-221210/17/2016

Yearly 3.3 million premature deaths occur worldwide due to air pollution and NOx pollution counts for nearly one seventh of those [1]. This makes exhaust after-treatment a very important research and has caused the permitted emission levels for NOx to decrease to very low levels, for EURO 6 only 0.4 g/kWh. Recently new legislation on ammonia slip with a limit of 10 ppm NH3 has been added [2], which makes the SCR-technology more challenging. This technology injects small droplets of an aqueous Urea solution into the stream of exhaust gases and through a catalytic reaction within the SCR-catalyst, NOx is converted into Nitrogen and Water. To enable the catalytic reaction the water content in the Urea solution needs to be evaporated and the ammonia molecules need to have sufficient time to mix with the gases prior to the catalyst. The μMist® platform technology, inspired by nature, uses heat in order to increase the fluid temperature above the required saturation temperature within its

Larsson, Peter, Lennard, Will, Dahlstrom, Jessica, Andersson, Oivind, Tunestal, Per

CFD Analysis of Tail Surface Modifications and Rudder Deflection Influence on I-28B Gyroplane at High Angle of Sideslip

F-0072-2016-11590

5/17/2016

In the following work a set of CFD computational cases was calculated in order to obtain the aerodynamic characteristics of I-28 gyroplane in a wide range of sideslip angle. Severe modifications were checked out, and most important on the directional stability components of forces and moments, acting on an airframe, have been shown in aerodynamic coefficient form. A part of these calculations was to test the influence of rudder deflection on baseline gyroplane aerodynamic properties. In order to compare the results with already flying example of gyroplane, with known, good flight characteristics, a geometry was reconstructed with low accuracy, but enough to obtain reasonable sideslip characteristics, especially for high sideslip angle.

Dziubinski, Adam, Ulma, Dawid, Zurawski, Rafal

Very-High Cycle Fatigue Testing Under Spectrum Loading for Endurance Limit Structural Design

F-0072-2016-11543

5/17/2016

A program has recently concluded that generated fatigue test data for the influence of a rotorcraft main rotor blade root bending spectrum (Helix) on the crack nucleation mechanisms in 7075-T651 aluminum. High frequency tests were performed that generated spectrum fatigue failures out to nearly 10⁹ cycles. Fractographic examination showed a distinct change in crack nucleation from slip initiated to inclusion initiated cracking as the spectrum peak stress level was increased. Spectrum life predictions were made using three different baseline constant-amplitude S-N curves, one using a traditional rotorcraft OEM fitting methodology, one using the HCF portion of a strain-life curve, and one that was fit to S-N data with test lives out to 3x10⁸ cycles. The spectrum life prediction using the S-N curve that properly modeled material behavior in the Very High-Cycle Fatigue (VHCF) regime provided a good correlation to the spectrum fatigue test data. Predictions using the other S-N curves were

Rusk, David, Taylor, Robert, Pregger, Bruce, Sanchez, Luis