Advanced 4 min read
Excessive Loss of Water from Main Engine Fresh Water Expansion Tank
Water from the Main Engine fresh water expansion tank is used for cooling purpose in the ship’s main engine. The…
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Advanced 3 min read
8 Engine Terms Every Marine Engineer Should Know
1. Viscosity of Oils Viscosity of oil is defined as the ability of the oil to flow. It is the property…
Recent Advancements in Air Technology 107 min read
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, and passenger cabins with a capacity of two passengers each. Unfortunately, the craft was not heated, so passengers were dressing heavy coats and covered with blankets during winter flights. As developments went on, the “Hindenburg” aircraft came with heated passenger area, larger dinning room, passengers lounge with a piano as the first audio entertainment, a decorated writing room, a more enhanced passenger cabins, and promenades with seating and windows that can be opened during the flight (Airships.net, Last visit 2011). In 1949, the “De Havilland DH 106 Comet” was the first commercial jet airliner to go into service. It had four jet engines located into the wings. It provided passengers with low-noise pressurized cabin (when compared to propeller-driven airliners), and large windows; hot and cold drinks, and food are serviced through the galley; separate women and men washrooms were available (Davies & Birtles, 1999). Starting from 1960, In-Flight Entertainment (IFE) systems started to attract attention; they were basically a pre-selected audio track that may be accompanied with a film projector. They had shown improvements in both vertical and horizontal dimensions. They expanded horizontally by improving the existing services; audio entertainment moved from using simple audio devices to surround sound and live radio; video display progressed from using a film projector, to CRT displays hanged in the ceiling, to LCD displays dedicated to each…
Recent Advancements in Air Technology 39 min read
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 power virtually all aircraft subsystem including flight control actuation, environmental control system and utility function. The concept offers advantages of reduced overall aircraft weight, reduced need for ground support equipment and maintenance and …
Social Media Marketing 7 min read
Social Media Marketing – Overview
Business in today’s day and age is dominated by customers and their demands. People prefer to see referrals, reviews over…
Construction Materials 1 min read
ALUMINIUM
It is present on the surface of earth crust in most of the rooks and clay. But to produce the…
Recent Advancements in Air Technology 50 min read
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 power electronic interfacing circuits. Also, the key design requirements for an interfacing circuit are addressed. Finally, a glance at protection facilities for the aircraft power system is given. More electric aircraft Recently, the aircraft industry has achieved a tremendous progress both in civil and military…
Recent Advancements in Air Technology 49 min read
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, practice and skills of pilot-operators. They may make decisions in situations characterized by a lack of information, human robust behaviors and their individual possibilities. These attributes as subjective factors have direct influences on the system characteristics, system quality and …
Recent Advancements in Air Technology 28 min read
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, the AR and AD problems are solved together by means of the theory of Constrained Integer Least-Squares (C-ILS). This theory extends the well-known least-squares theory (LS), by having geometrical constraints as well as integer constraints imposed on parameter subsets. The novel AR-AD estimation problem is discussed and its various properties are analyzed. The method’s complexity is addressed by presenting new numerical algorithms that largely reduce the required processing load. The main objective of this chapter is to provide evidence that: • GNSS carrier-phase based attitude determination is a viable alternative to existing attitude sensors • Employing the new ambiguity-attitude estimation method enhances ambiguity resolution…
Recent Advancements in Air Technology 27 min read
Introduction to Influence of Forward and Descent Flight on Quadrotor Dynamics
The focus of this chapter is an aircraft propelled with four rotors, called the quadrotor. Quadrotor was among the first rotorcrafts ever built. The first successful quadrotor flight was recorded in 1921, when De Bothezat Quadrotor remained airborne for two minutes and 45 seconds. Later he perfected his design, which was then powered by 180-horse power engine and was capable of carrying 3 passengers on limited altitudes. Quadrotor rotorcrafts actually preceded the more common helicopters, but were later replaced by them because of very sophisticated control requirements Gessow & Myers (1952). At the moment, quadrotors are mostly designed as small or micro aircrafts capable of carrying only surveillance equipment. In the future, however, some designs, like Bell Boeing Quad TiltRotor, are being planned for heavy lift operations Anderson (1981); Warwick (2007). In the last couple of years, quadrotor aircrafts have been a subject of extensive research in the field of autonomous control systems. This is mostly because of their small size, which prevents them to carry any passengers. Various control algorithms, both for stabilization and control,…
Recent Advancements in Air Technology 60 min read
Introduction to Study of Advanced Materials for Aircraft Jet
Engines Using Quantitative Metallography The aerospace industry is one of the biggest consumers of advanced materials because of its unique combination of mechanical and physical properties and chemical stability. Highly alloyed stainless steel, titanium alloys and nickel based superalloys are mostly used for aerospace applications. High alloyed stainless steel is used for the shafts of aero engine turbines, titanium alloys for compressor blades and finally nickel base superalloys are used for the most stressed parts of the jet engine – the turbine blades. Nickel base superalloys were used in various structural modifications: as cast polycrystalline, a directionally solidified, single crystal and in last year’s materials which were produced by powder metallurgy.…
Recent Advancements in Air Technology 24 min read
Introduction to Variational Approach to the Fuel Optimal
Control Problem for UAV Formations The pivotal role of unmanned aerial vehicles (UAVs) in modern aircraft technology is evidenced by the large number of civil and military applications they are employed in. For example, UAVs successfully serve as platforms carrying payloads aimed at land monitoring (Ramage et al., 2009), wildfire detection and management (Ambrosia & Hinkley, 2008), law enforcement (Haddal & Gertler, 2010), pollution monitoring (Oyekan & Huosheng, 2009), and communication broadcast relay (Majewski, 1999), to name just a few. A formation of UAVs, defined by a set of vehicles whose states are coupled through a common control law (Scharf et al., 2003b), is often more valuable than a single aircraft because it can…
