This seminar will present an introduction to Vehicle Dynamics from a vehicle system perspective. The theory and applications are associated with the interaction and performance balance between the powertrain, brakes, steering, suspensions and wheel and tire vehicle subsystems. The role that vehicle dynamics can and should play in effective automotive chassis development and the information and technology flow from vehicle system to subsystem to piece-part is integrated into the presentation. Governing equations of motion are developed and solved for both steady and transient conditions.
One of the most important safety critical components on cars, trucks, and aircraft is the pneumatic tire. Vehicle tires primarily control stopping distances on wet and dry roads or runways and strongly influence over-steer/under-steer behavior in handling maneuvers of cars and trucks. The inflated tire-wheel assembly also acts as a pressure vessel that releases a large amount of energy when catastrophically deflated. The tire can also serve as a fulcrum, both directly and indirectly, in contributing to vehicle rollover. This seminar covers these facets of tire safety phenomena.
This interactive seminar will take you beyond the basics of passenger car and light truck vehicle dynamics by applying advanced theory, physical tests and CAE to the assessment of ride, braking, steering and handling performance. Governing state-space equations with transfer functions for primary ride and open loop handling will be developed & analyzed. Building on the analysis of the state space equations, common physical tests and their corresponding CAE solutions for steady state and transient vehicle events will be presented. The "state-of-the-art" of vehicle dynamics CAE will be discussed.
While a variety of new engineering methods are becoming available to assist in creating optimal vehicle designs, subjective evaluation of vehicle dynamics is still required to deliver desired braking, handling, and acceleration attributes. In order to better prepare today’s engineer for this task, this course offers modules devoted to twelve key fundamental principles associated with longitudinal and lateral vehicle dynamics. Each focused classroom session is paired with an on-track exercise to immediately reinforce these concepts with a dedicated behind-the-wheel driving session, effectively illustrating these principles in the real world.
Active Safety, Advanced Driver Assistance Systems (ADAS) are now being introduced to the marketplace as they serve as key enablers for anticipated autonomous driving systems. Automatic Emergency Braking (AEB) is one ADAS application which is either in the marketplace presently or under development as nearly all automakers have pledged to offer this technology by the year 2022. This one-day course is designed to provide an overview of the typical ADAS AEB system from multiple perspectives.
This seminar provides an introduction to the fundamental concepts and evolution of passenger car and light truck 4x4/all-wheel drive (AWD) systems including the nomenclature utilized to describe these systems. Basic power transfer unit and transfer case design parameters, component application to system function, the future of AWD systems, and emerging technologies that may enable future systems are covered. This course is an excellent follow-up to the 98024-A Familiarization of Drivetrain Components seminar (which is designed for those who have limited experience with the total drivetrain).
The current paper deals with the numerical study of the downwash flowfield characteristics in a cycloidal rotor. In an aircraft equipped with this kind of thruster, the downwash flow plays significant role in different flight modes. The interaction of this downwash jet with ground in effective height levels is studied using CFD simulations. Several operating conditions like pitching oscillation angles, rotation speeds and height levels are all considered in this work. The results declare that close-ground operating states augments the efficiency of cyclorotor. The vertical and horizontal forces of a single blade is also analyzed in a complete cycloid in different operating conditions. A lead and lag in maximum and minimum extremes of force curves of a single blade cycloid is obtained while being subjected to different functional conditions.
Aircraft equipment is operated in a wide range of external conditions, which, with a certain combination of environmental parameters, can lead to icing of the engine internal elements. Due to icing, the engine components performance change what leads to decrease in thrust, gas dynamic stability, durability, etc. Safe aircraft operation and its desired performance may be lost as a result of such external influence. Therefore, it is relevant to study the possibilities of reducing the icing effect with the help of a special engine control. The focus of this paper is to determine control methods of an aircraft gas turbine engine addressing this problem. The object of the study is a modern commercial turbofan with a bypass ratio of about 9. In this paper analysis of the effect of ice crystal icing on the engine components performance is conducted.
Delayed Detached Eddy Simulations (DDES) of separating-reattaching flows on the suction side of an ice-contaminated airfoil were conducted. A single-section straight-wing NACA23012 airfoil with leading-edge ice was studied. The geometry represents a realistic glaze horn-ice contamination obtained during the icing test campaigns described in , which has aerodynamic data for comparison. The three-dimensional transient flow behavior was simulated using the open-source flow solver OVERFLOW, version 2.2l  developed by NASA Langley Research Center. Configurations at three angles of attack that exhibit unsteady flow behavior starting with the bursting angle were examined at Mach number of 0.18 and Reynolds number of 1.8x106. As the stall angle was approached the aerodynamic performance parameters displayed large-scale unsteadiness where periods of attached and separated flows were observed. The time-averaged results show good agreement with the aerodynamic test data.
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.
A 3D CFD methodology is presented to simulate ice build-up on propeller blades exposed to known icing conditions in flight, with automatic blade pitch variation at constant RPM to maintain the desired thrust. One blade of a six-blade propeller and a 70-passenger twin-engine turboprop are analyzed as stand-alone components in a multi-shot quasi-steady icing simulation. The thrust that must be generated by the propellers is obtained from the drag computed on the aircraft. The flight conditions are typical for a 70-passenger twin-engine turboprop in a holding pattern in Appendix C icing conditions: 190 kts at an altitude of 6,000 ft. The rotation rate remains constant at 850 rpm, a typical operating condition for this flight envelope.