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This paper presents an approach to numerically simulate greenhouse windnoise. The term “greenhouse windnoise” here describes the sound transferred to the interior through the glass panels of a series vehicle. Different panels, e.g. the windshield or sideglass, are contributing to the overall noise level. Attached parts as mirrors or wipers are affecting the flow around the vehicle and thus the pressure fluctuations which are acting as loads onto the panels. Especially the wiper influence and the effect of different wiper positions onto the windshield contribution is examined and set in context with the overall noise levels and other contributors. In addition, the effect of different flow yaw angles on the windnoise level in general and the wiper contributions in particular are demonstrated. As computational aeroacoustics requires accurate, highly resolved simulation of transient and compressible flow, a Lattice-Boltzmann approach is used.

Environmental sustainability is morphing Automotive technical development strategies and driving the evolution of vehicles with a speed and a strength hardly foreseeable a decade ago. The entire vehicle architecture is impacted, and energy efficiency becomes one of the most important parameters to reach goals, which are now not only market demands, but also based on regulatory standards with penalty consequences. Therefore, rolling drag from all bearings in multiple rotating parts of the vehicle needs to be reduced; wheel bearings are among the biggest in size regardless of the powertrain architecture (ICE, Hybrid, BEV) and have a significant impact. The design of wheel bearings is a complex balance between features influencing durability, robustness, vehicle dynamics, and, of course, energy efficiency.

A flight test yaw damper for Dutch roil damping improvement has been designed for the Starship flying scale prototype. An analytical study was also performed using linear analysis of a wide variety of flight conditions. Flight test results confirmed a noticeable improvement in ride qualities with the yaw damper engaged. An unexpected benefit was improved directional handling qualities during deep-stall testing.

This paper describes a numerical method for solving three-dimensional incompressible flow problems and its use in predicting the aerodynamic characteristics of V/STOL aircraft. Arbitrary configuration and inlet geometry, fan inflow distributions, thrust vectoring, jet entrainment, angles of yaw, and flight speeds from hover through transition can be treated. Potential-flow solutions are obtained with the method of influence coefficients, using source and doublet panels distributed on the boundary surfaces. The results include pressure distributions, lift, induced drag and side force, and moments. Theoretical solutions are presented for clean lifting wings and for a NASA fan-in-wing model. Comparisons with the experimental NASA data demonstrate the validity of the approach and uncover the importance of viscous effects, fan inflow distribution, and jet entrainment.

The author proposes a new principle of suspension system. First, a new shock isolation method prevents sudden sharp jolts and enables a body to continue in motion as before, by transforming linear motion into circular motion. This method reduces abrupt deceleration and impact force. Next, we examined the gravity spring action of a pendulum as a new vibration isolation method. Because the pendulum generates longitudinal vibration, it has isolation effect against the longitudinal vibration input. Application of this new principle to aircrafts, automobiles, motorcycles, and even to bicycles and wheelchairs, overcomes the limitations of current technology. This study focused on two as-yet-unresolved safety problems of aircraft undercarriages. One is acceleration impact on the wheels; the other is collision with an obstacle on the runway.

Although autonomous driving technology has become an emerging research focus, safety is still the most crucial concern when autonomous vehicles leave research laboratory and enter public traffic. Direct yaw moment control (DYC), which differentially brakes the wheels to produce a yaw moment, is an important system to ensure the driving stability of vehicle under extreme conditions. Traditional DYC system must need to take into account driver’s intention and vehicle dynamics. However, for autonomous vehicle, no human is involved in driving process, and enforcing traditional DYC system may conflict with the demands of the desired path. Therefore, in this paper, a novel DYC system for autonomous vehicle is proposed to simultaneously suppress lateral path tracking deviation while maintaining autonomous vehicle stability at or close to the driving limits. In the hardware aspect, an integrated-electro-hydraulic brake (IEHB) actuator scheme is adopted.

This paper describes a project to build a practical flying car called Starcar 4. The vehicle actually is more like a flying motorcycle, since it uses three wheels on the road. It has a single seat and weighs a little less than 1200 lbs, so it could be certified as a primary class airplane. The vehicle is practical in the sense that it is about as light and simple as its mission allows. A single engine is used to propel the vehicle on the road and in the air. When not in use, the wings hang on the sides, and the driver plugs them into the fuselage when he wants to fly. Most functions serve in both road and sky modes. The driver can do an aerodynamic wheelie on the ground, and he will shift into fourth gear when he reaches cruise altitude.

A semi-active gravity gradient attitude stabilization system (SAGS) providing active pitch control and semi-passive roll/yaw control has been developed. The design and development of the SAGS controller for space flight test on the NASA developed PAC secondary payload spacecraft are described and performance predictions are presented for the first flight test scheduled in August 1969. Initial in-orbit performance of Delta PAC-1 is summarized.

In power-split configuration, the input power is split into two parts, one of which is transmitted from the internal combustion engine through one or more planetary gear(s) to the wheels. The other part is generated as electricity and passes through an electrical variator to assist the driving torque. The latter has the characteristic of poor efficiency. In this simulation study, a comparison among the input power-split, compound power-split, and two mode power-split are discussed. Output power-split is not mentioned in this paper due to its limited applicability in specific vehicles. The idea of selection of the electrical machines is explained: the speed and torque of electrical machines was taken into consideration for the required transmission ratios spread.

Brake pulsation is a low frequency vibration phenomenon in brake judder. In this study, a simulation approach has been developed to understand the physics behind brake pulsation employing a full vehicle dynamics CAE model. The full vehicle dynamic model was further studied to understand the impact of suspension tuning variation to brake pulsation performance. Brake torque variation (BTV) due to brake thickness variation from uneven rotor wear was represented mathematically in a sinusoidal form. The wheel assembly vibration from the brake torque variation is transmitted to driver interface points such as the seat track and the steering wheel. The steering wheel lateral acceleration at the 12 o’clock position, driver seat acceleration, and spindle fore-aft acceleration were reviewed to explore the physics of brake pulsation. It was found that the phase angle between the left and right brake torque generated a huge variation in brake pulsation performance.

This paper summarizes the main considerations in applying a Twin Gyro Controller and the problems in implementing such a controller. Several Twin Gyro Controllers have been built for the purpose of measuring disturbances on a space vehicle, and the construction problems encountered are reported. The main problem areas encountered involved alignment torquing provisions and mechanical tolerances. The three-axis Twin Gyro Controller was spun up to synchronous speed before launch and, as a result, the spinning of the spin stabilized vehicle introduced additional loads on the gyro wheels and torquers. These loads resulted in the use of a spiroid gear drive in the gyro torquer closed loop. Considerations in applying the Twin Gyro Controller as an attitude controller and as a measurement device are covered in terms of sensitivity, accuracy, and limitations.

An outer loop guidance architecture was designed to control autonomous aerial refueling mission from the trail aircraft side. The design utilized bank, yaw rate, velocity and climb rate commands implemented using a previously developed adaptive trajectory concept. The concept was based on position error feedback that was used to control trail aircraft overshoot and tracking about the lead aircraft refueling point. To demonstrate this application, an open loop linear trail aircraft model at a given flight condition was selected. Inner loop control laws were designed using Linear Quadratic Regulator feedback controller and Balanced Deviation theory. The outer loop guidance architecture was then added to implement the application. The performance of the system was then evaluated for a selected position error, and disturbance.

The aerodynamic drag characteristics of a passenger car are typically defined by a single parameter, the drag coefficient at zero yaw angle. While this has been acceptable in the past, it may not allow a true comparison between vehicles with regard to the impact of drag on performance, especially fuel economy. An alternative measure of aerodynamic drag should take into account the effect of non-zero yaw angles and some proposals have been made in the past, including variations of wind-averaged drag coefficient. For almost all cars the drag increases with yaw, but the increase can vary significantly between vehicles. In this paper the effect of various parameters on the drag rise with yaw are considered for a range of different vehicle types. The increase of drag with yaw is shown to be an essentially induced drag, which is strongly dependent on both side force and lift. Shape factors which influence the sensitivity of drag with yaw are discussed.

Targets for reducing emissions and improving energy efficiency present the automotive industry with many challenges. Passenger cars are by far the most common means of personal transport in the developed part of the world, and energy consumption related to personal transportation is predicted to increase significantly in the coming decades. Improved aerodynamic performance of passenger cars will be one of many important areas which will occupy engineers and researchers for the foreseeable future. The significance of wheels and wheel housings is well known today, but the relative importance of the different components has still not been fully investigated. A number of investigations highlighting the importance of proper ground simulation have been published, and recently a number of studies on improved aerodynamic design of the wheel have been presented as well. This study is an investigation of aerodynamic influences of different tires.

Side force has an influence on the behaviour of passenger cars in windy conditions. It increases approximately linearly with yaw angle over a significant range of yaw for almost all cars and the side force derivative, (the gradient of side force coefficient with yaw angle), is similar for vehicles of a given category and size. The shape factors and components which affect side force for different vehicle types are discussed. The dominant influence on side force, for most cars, however, is shown to be the vehicle height which is consistent with slender wing theory if the car and its mirror image are considered. This simple theory is shown to apply to 1-box and 2- box shapes, covering most MPVs, hatchbacks and SUVs, but does not adequately represent the side forces on notchback and fastback car shapes. Data from simple bodies is used to develop a modification to the basic theory, which is applied to these vehicle types.

An interconnection between the roll and yaw control may function as a device for coordinating the two controls, or as a means for increasing the effective dihedral, or both. The coordinating function may be interpreted in terms of adjusting the overall level of aileron yaw; this can improve roll and yaw response to roll control inputs. The interconnect function of increasing effective dihedral is of questionable value, and some undesirable side effects might be avoided if it were not employed.

A two-phase digital simulation of the effect of Reaction Controls on high-angle of attack has been conducted. The first phase conducted at the DAvid W. TAylor Naval Ship R&D Center sized and developed the reaction control system for a modern high performance fighter aircraft. The results of this phase indicated increased roll response due primarily to increased yaw control power. The second phase was a manned one-on-one study conducted at the NASA Langley Differential Maneuvering Simulator using Navy/Marine pilots. Results of this study indicated a 4 to 1 Time on Advantage ratio for the reaction controlled aircraft from a neutral start position. Time on Advantage ratios were 1.66 to 1 and 28 to 1 when the reaction controlled aircraft was placed at a disadvantage and advantage respectively.

Turbine wheel containment on air turbine starters has been standard practice for many years. Proven methods of designing reliable containment rings combine theoretical analyses and empirical relationships derived from large-scale testing programs. The choice of design and material must consider energy absorption, piercing resistance, and the effects on the surrounding static structure due to ring expansion and movement. New concepts such as dual-alloy rings may offer improvements in weight or reliability.

The benefits of pitch/yaw thrust vectoring and/or thrust reversing multi-function nozzles (MFN) for fighter type aircraft have been identified relative to the air-to-air mission in several previous papers. This paper will point out those previously noted payoffs which also apply to air-to-ground attack fighters. It will also present a detailed description of air-to-ground unique multi-function nozzle benefits. Specific treatment will be given to close air support, battlefield interdiction, suppression of enemy air defenses, and deep strike missions. MFN contributions to air-to-ground survivability and effectiveness will be emphasized relative to the critical aspects of basing, ingress, target attack, self defense, egress and recovery. Actual air-to-ground attack historical data will be employed as it is applicable to this discussion.