Methods to Measure Bearing Clearance
There are various types of methods adopted by different marine engine manufacturers to measure the clearance of main bearing of marine engine. Following are some of the most prominent methods…
Terms Associated with Turbocharger Surge
Surge pressure dip: The surge cycle has a specific pressure dip and if the cycle continues without changing the operating point, the size of the pressure dip will sustain. Surge cycle…
What is Turbocharger Surging?
Turbocharger is one of the most important parts of the main propulsion system of the ship. Turbocharger surging is a phenomenon, which affects the performance of the turbocharger and reduces…
Breaking-In and Running-In in Marine Diesel Engines
One cannot imagine a ship unequipped with marine engines as they are responsible for propulsion and power generation for the vessel. Two or Four stroke engines are used for propelling…
How Massive Main Engines are Fitted in the Ship’s Engine Room?
A ship’s main engine is a massive structure with an average height of about 3 to 4 storey building (approx. 45 feet) and weight equals to 500 giant African elephants…
Main Engine Performance Curve
After the building of the ship is complete and before handing over it to the owners, sea trials are done to test that the ship is able to deliver the…
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 water in the tank needs to be kept at the…
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 of the liquid which tends to prevent relative movement between…
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 passenger. The vertical improvement was noticed through introducing new technologies; cabin telephones allowed passengers to make phone calls during the flight; the system become interactive and allowed passengers to select their own services, while in the past they were forced to follow fixed services; web-based internet services allowed passengers to use some services such as emails and SMS messaging. The basic idea behind IFE systems was to provide passengers with comfortableness during their long range flights; especially with long transatlantic flights where passengers see nothing but a large blue surface, so that services were initially based on delivering food and drinks to passengers. As passengers demand for more services grows, accompanied with an increase in airlines competition and technology advancement, more services were introduced and modern electronic devices played a remarkable role. This caused a change in the basic concept behind IFE systems; it becomes more than just giving physical comfortableness and providing food. It is extended to provide interactive services that allow passengers to participate as a part of the entertainment process as well as providing business oriented services through connectivity tools. Moreover, it can provide means of health monitoring and physiological comfort. In recent years, market surveys have revealed …
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 increased reliability (Taha,2007,Wiemer,1999). Many aircraft power systems are now operating with a variable frequency over a typical range of 360 Hz to 800 Hz. Distribution voltages for an aircraft system can be classified as: a. Nominal 115/200 V rms and 230/400 V rms ac, both one phase and three phase, over variable frequency range. b. Nominal 14, 28 and …
