Search Results

This presentation proposes an approach to use ABS wheel speed sensor signals together with other vehicle state information from a brake control module to detect an unbalanced tire or tires in real-time. The proposed approach consists of two-stage algorithms that mix a qualitative method using band-pass filtering with a quantitative parameter identification using conditional least squares. This two-stage approach can improve the robustness of tire imbalance or imbalances. The proposed approach is verified through vehicle testing and the test results show the effectiveness of the approach. Presenter Jianbo Lu, Ford Motor Co.

Abstract The preliminary gas turbine combustor design process uses a huge amount of empirical correlations to achieve more optimized designs. Combustion efficiency, in relation to the basic dimensions of the combustor, is one of the most critical performance parameters. In this study, semi-empirical correlations for combustion efficiencies are examined and correlation coefficients have been revised using an experimental air-blasted tubular combustor that uses JP8 kerosene aviation fuel. Besides, droplet diameter and effective evaporation constant parameters have been investigated for different operating conditions. In the study, it is observed that increased air velocity significantly improves the atomization process and decreases droplet diameters, while increasing the mass flow rate has a positive effect on the atomization—the relative air velocity in the air-blast atomizer increases and the fuel droplets become finer.

Abstract The vibration behavior of components exposed to aerodynamic loads must be taken into consideration when designing aerial vehicles. Numerical simulation plays a key role in developing more realistic analytical models for panel flutter analysis. The notable feature of the present research is the use of two methods for the aeroelastic analysis of two-dimensional curved panels with cylindrical bending. In the first approach, the finite volume method (FVM) is used for supersonic viscous flow and nonlinear structural model while full Navier-Stokes equations are discretized. In the second approach, the third-order nonlinear piston theory aerodynamics in addition to mechanical and thermal loads is assumed. Moreover, the semi-analytical weighted residual method for the nonlinear curved panel is utilized. These approaches are concurrently compared with each other for the first time. Furthermore, Hamilton’s principle is used and partial differential equations (PDEs) are derived.

The 25 papers in this technical paper collection cover aerodynamics development, fuel economy, unsteady aerodynamics, cooling airflow, fundamental aerodynamics, and test facilities.

This document outlines historical systems which have used the landing gear as a sensor or installation point for full aircraft weight and balance systems. A number of systems have been developed, installed, certified, and placed in service but few systems remain in regular use. The document will capture the history of these systems, reasons (where known) for their withdrawal from service, and lessons learned.

This report will document Runway Condition Monitoring systems that provide information intended to reduce or eliminate aircraft runway excursions or overruns that may occur as a result of poor runway conditions.

This SAE Aerospace Information Report (AIR) provides technical information regarding Engine Control Systems Interdependencies strategies and/or functions. This concerns aircraft with multiple power sources: at least two engines, whatever the nature of the power source is (electrical motor or gas turbine engine). Within this document the aircraft stands for fixed-wing aircraft as well as rotorcraft. The term EECS or FADEC is used for the engine electronic control system, whereas the term EEC is used for the electronic unit itself. The scope includes civilian aircraft powered by turbofan, turboprop, turboshaft and electrical engines equipped with electronic engine controls. Military aircraft is taken into consideration, however restricted topics that change the operational behaviors are not discussed.

The scope of the test method is to provide stakeholders including fluid manufacturers, brake manufacturers, aircraft constructors, aircraft operators and airworthiness authorities with a relative assessment of the effect of deicing chemicals on carbon oxidation. This test is designed to assess the relative effects of runway deicing chemicals by measuring mass change of contaminated and bare carbon samples tested under the same conditions.

This document was requested by the FAA to provide a technical update of TSO-C26d to address Electric Brake Actuation, standardize with TSO-C135a and address any remaining concerns with the current technical requirements in AIR5381.

This SAE Aerospace Standard (AS) prescribes the Minimum Performance Standards (MPS) for environmental conditions that wheel, brake, and wheel and brake assemblies to be used on aircraft certificated under 14 CFR Parts 23, 25, 27, and 29. The environmental requirements in this document shall be used in conjunction with other MPS defined in Technical Standard Orders for the applicable equipment.

The E-36 committee is requested to develop a standard or recommended practice for Control System Fault Accommodation to provide guidance on the fault detection and accommodation strategies and robust validation toward certification to FAA Control System regulation 33.28. FAA has written an issue paper on this outlining the risks and vulnerabilities in fault detection/ accommodation based on industry/agency experience over many years; and suggested means of compliance in terms of tests, analyses, simulations. The E-36 is requested to factor in the issue paper and build on the guidance content into an SAE document for reference by the industry. In this endeavor, it is recommended that the SAE standard/ARP consider conventional gas turbine controls as well as emerging architectures such Hybrid and Electric Propulsion Systems.

Publicize Aircraft Recommended Practice for Missionized Wear Testing on Wright Patterson’s Landing Gear Test Facility’s 168i dynamometer.

Integrating the seemingly divergent objectives of aircraft seat configuration is a difficult task. Aircraft manufacturers look to design seats to maximize customer satisfaction and in-flight safety, but these objectives can conflict with the profit motive of airline companies. In order to boost revenue by increasing the number of passengers per aircraft, airline companies may increase seat height and decrease seat pitch. This results in disaccommodation of a greater percentage of the passenger population and is a reason for rising customer dissatisfaction. This paper describes an effort to bridge this gap by incorporating digital human models, layout optimization, and a profit-maximizing constraint into the aircraft seat design problem. A simplified aircraft seat design experiment is conceptualized and its results are extrapolated to an airline passenger population.

Scope of the DRESS project is to research, develop and validate a distributed and redundant electrical steering system technology for an aircraft nose landing gear. The new system aims to: • reduce system weight at aircraft level, replacing the current hydraulic actuation system with an electric one. • improve aircraft safety, achieving higher system redundancy levels compared to the current technology capabilities. This paper presents an outline of different activities occurring in the DRESS project and also shows preliminary results of the new system performance.

For actuation of high lift surfaces in modern airplanes, complex mechanical shaft transmission systems powered by central drive units are deployed. The design of mechanical actuation systems, which have a major share in the weight of secondary flight controls, is a complex and challenging engineering task. Especially for specification of essential component and system design parameters within the preliminary design phase, engineering skill and experience are of significant importance owing to many uncertainties in component data and boundary conditions. Extensive trade-offs, as well as an evaluation of the system requirements and constraints lead to an iterative and time-consuming design process. Utilizing an integrated design assistance tool, mathematical functions and constraints can be modeled on system and component level and formalized as a constraint satisfaction problem (CSP). Thus, automated consistency checking and pruning of the solution space can be achieved.

In several industrial fields, the integration of functions is a key technology to enhance the efficiency of components in terms of performance to mass/volume/cost ratio. Concerning the space industry, in the last few years the trend in spacecraft design has been towards smaller, light-weight and higher performance satellites with sophisticated payloads and instrumentation. Increasing power density figures are the common feature of such systems, constituting a challenging task for the Thermal Control System. The traditional mechanical and thermal design concepts are evidencing their limits with reference to such an emerging scenario.

Wet clutches are important components used in the transmission and drive trains of many modern vehicles. The clutches transfer torque via the friction between a number of friction discs and the friction characteristics is therefore of great importance for the overall behavior of the vehicles. The friction characteristics is governed by a number of parameters such as lubricant base oil and additives, type and permeability of the friction material and temperature and surface roughness of the interacting surfaces. The permeability is considered to influence time of engagement and supply the sliding interface with lubricant and additives during engagement. In this work, a permeability measurement method suitable for wet clutch friction materials is thus used to measure the permeability of friction materials of different types; sintered bronze and paper based materials.