Active Flow Control by Using Plasma Actuators
Abstract Active flow control has recently received an increasing attention since it…
Progress in Experimental Research of Turbine Aeroacoustics
Abstract Modifications on the intermediate turbine duct in order to reduce noise…
Introduction to Study of Effects of Lightning Strikes to an Aircraft
It is difficult to avoid thunderstorm regions by aircraft, so that on average every commercial airliner is struck by lightning once per year. Defining test and design criteria of aircraft is becoming important since aircraft safety is increasingly dependent on electronic equipment and the development of new materials (carbon composites, etc.) to replace the metallic airframes. In-flight statistics show that most strikes occurred 3-5 km above sea level, where the temperature is ~ 0C (Uman & Rakov, 2003; Larsson, 2002). There are two different types of lightning strikes to aircraft. The first type is that the aircraft initiates the lightning discharge when it is found in the intense electric field region of a thundercloud,…
Introduction toSynthetic Aperture Radar Systems for Small Aircrafts: Data Processing Approaches
The synthetic aperture radar (SAR) is considered now as the most effective instrument for producing radar images of ground scenes with a high spatial resolution. The usage of small aircrafts as the platform for the deployment of SAR systems is attractive from the point of view of many practical applications. Firstly, this enables for a substantial lowering of the exploitation costs of SAR sensors. Secondly, such solution provides a possibility to perform a rather quick surveillance and imaging of particular ground areas. Finally, the progress in…
Introduction To Analysis of the Maintenance Process of the Military Aircraft
This chapter presents the analysis of the maintenance process of a military aircraft with a detailed description of two areas, i.e. the process of maintaining and the process of operating. Each of these processes is briefly characterized. The section also involves methods enabling the determination of: residual durability of specified devices/systems of a military aircraft on the basis of the diagnostic parameters of these devices/systems, and the effectiveness of a combat task execution on the basis of information registered in the process…
Introduction to Key Factors in Designing In-Flight Entertainment Systems
Most of researches concerning In-Flight Entertainment (IFE) systems are done on case bases without a global view that encompasses all IFE components. Thus, we try to highlight the key factors of designing IFE system, and showing how its various components can integrate together to provide the required services for all parties involved with the system. Background and historical issues Flight entertainment started before the First World War by the Graf Zeppelin (see Figure 1). This aircraft had a long, thin body with a teardrop shape; it was about 776 feet long and 100 feet in diameter, filled with hydrogen, and the cabin was located under the hull; five engines were fixed to the hull to power the aircraft. Fig. 1. The Graf Zeppelin aircraft From the passengers comfort perspective, this model was equipped with a kitchen having electric ovens and a refrigeration unit, a small dinning room, washrooms for men and women,…
Introduction to Power Electronics Application for More Electric Aircraft
In the competitive world of airline economics, where low cost carriers are driving dawn profit margins on airline seat miles, techniques for reducing the direct operating costs of aircraft are in great demand. In effort to meet this demand, the aircraft manufacturing industry is placing greater emphasis on the use of technology, which can influence maintenance costs and fuel usage. (Faleiro, 2005) There is a general move in the aerospace industry to increase the amount of electrically powered equipments on future aircraft. This trend is referred to as the “More Electric Aircraft”. It assumes using electrical energy instead of hydraulic, pneumatic and mechanical means to …
Introduction to Power Generation and Distribution System for a More Electric Aircraft
More-Electric Aircraft (MEA) is the future trend in adopting single power type for driving the non-propulsive aircraft systems; i.e. is the electrical power. The MEA is anticipated to achieve numerous advantages such as optimising the aircraft performance and decreasing the operation and maintenance costs. Moreover, MEA reduces the emissions of air pollutant gases from aircrafts, which can contribute in signifcantly solving some of the problems of climate change. However, the MEA puts some challenges on the aircraft electrical system, both in the amount of the required power and the processing and management of this power. This chapter introduces the outline for MEA. It investigates possible topologies for the power system of the aircraft. The different electric power generation options are highlighted; while at the same time assessing the generator topologies. It also includes a general review of the …
Introduction to Subjective Factors in Flight Safety
The central deterministic element of the aircraft conventional control systems is the pilot – operator. Such systems are called as active endogenous subjective systems, because (i) the actively used control inputs (ii) origin from inside elements (pilots) of the system as (iii) results of operators’ subjective decisions. The decisions depend on situation awareness, knowledge,…
Introduction to GNSS Carrier Phase-Based Attitude Determination
The GNSS (Global Navigation Satellite Systems) are a valid aid in support of the aeronautic science. GNSS technology has been successfully implemented in aircraft design, in order to provide accurate position, velocity and heading estimations. Although it does not yet comply with aviation integrity requirements, GNSS-based aircraft navigation is one of the alternative means to traditional dead-reckoning systems. It can provide fast, accurate, and driftless positioning solutions. Additionally, ground-based GNSS receivers may be employed to aid navigation in critical applications, such as precision approaches and landings. One of the main issues in airborne navigation is the determination of the aircraft attitude, i.e., the orientation of the aircraft with respect to a defined reference system. Many sensors and technologies are available to estimate the attitude of a aircraft, but there is a growing interest in GNSS-based attitude determination (AD), often integrated at various levels of tightness to other types of sensors, typically Inertial Measurements Units (IMU). Although the accuracy of a stand-alone GNSS attitude system might not be comparable with the one obtainable with other modern attitude sensors, a GNSS-based system presents several advantages. It is inherently driftless, a GNSS receiver has low power consumption, it requires minor maintenance, and it is not as expensive as other high-precision systems, such as laser gyroscopes. GNSS-based AD employs a number of antennas rigidly mounted on the aircraft’s structure, as depicted in Figure 1. The orientation of each of the baselines formed between the antennas is determined by computing their relative positions. The use of GNSS carrier phase signals enables very precise range measurements, which can then be related to angular estimations. However, carrier phase measurements are affected by unknown integer ambiguities, since only their fractional part is measured by the receiver. The process of reconstructing the number of whole cycles from a set of measurements affected by errors goes under the name of ambiguity resolution (AR). Only after these ambiguities are correctly resolved to their correct integer values, will reliable baseline measurements and attitude estimations become available. This chapter focuses on novel AR and AD methods. Recent advances in GNSS-based attitude 2 Will-be-set-by-IN-TECH determination have demonstrated that the two problems can be formulated in an integrated manner, i.e., aircraft attitude and the phase ambiguities can be considered as the unknown parameters of a common ambiguity-attitude estimation method. In this integrated approach,…
