Tuesday, May 5, 2020

Business and Corporate Aviation Method †MyAssignmenthelp.com

Question: Discuss about the Business and Corporate Aviation Management. Answer: Introduction: The electrical power system is normally confined to lower rated and also the control system. Initially, the airframes made use of 115 Voltage AC at a frequency of 400 Hz to supply the greater loads. The system was built with the rectifiers known as Transformers Rectifiers Units (true). These are some of the characteristics of the electrical power generation in aircraft. In electrical power generation employs the use of alternators which uses the rotating magnetic field to help generate electric power. The alternators create electromagnet. This type of generation also employs the use the diodes which are used to rectify the alternating power from the alternator. This rectification is highly important in the aircraft since most of the component in the aircraft uses the DC power, but in the alternator, it is AC which is generated. The power generated is sometimes stored by the help of the batteries to help avoid wastage of electrical power. The electrical power generated to be used in the aircraft is made true by the help of the rotating parts (mechanical) parts which hence rotate and help generate electrical power. The efficiency electrical power is relatively lower as compared to the mechanical power and fluid power. Generation of electrical power is purely by the use of chemical energy where there are some electrochemical reactions taking place to help dislodge electrons and hence flow of electrons. Electrical power generation used in aircraft also makes good use of inductors which are cut by the electromagnetic rod. The interaction of the electromagnetic rod and the inductors help in generation of electrical (theory based on the faradays law). Energy is generated mechanically from the GT core; the energy is converted in the process of traditional GT system(Calse, 2014). Mechanical offtake from the spinning engine spool in the aircraft and all other moving parts which are employed to help in the creation of power. This power can be used to drive several auxiliary loads which constitute hydraulic and electrical generator. Even though mechanical power is not the sole source of the power used in the aircraft, the power generated mechanically from the GT spools has highly increased. The below are some characteristics of the mechanical power generation. Mechanical power generation fully makes use of kinetic energy to help generate electrical power ( the rotating parts) This type of power generation copes power to realize any task which involves forces and movement. In other words, mechanical power generation majorly deals with forces. This type of power generation of power in an aircraft also involves the use of machines and related engines which cause movement which is used to make the parts of the aircraft to move. This type constitutes actuators which create movements and force which rotates the rotors part in the aircraft. Mechanical involves crank shafts and movements of pistons which reciprocate in the cylinder to create mechanical power. This system also has the rotating pulley which is employed to generate power used in aircraft. All components in mechanical power generation are a solid state which just rotates hence their power efficiency is relatively high because power losses are reduced. And this is improved when the frictions which may occur is fully reduced. Fluid power is also known as the fluid power which is power transferred by the help of the organized circulation of fluid under high pressure in an aircraft. These are some of the properties of the fluid power generation, the fluid used in the aircraft is usually water-glycol mixture or water soluble oil(Fallucco, 2013). This fluid is supplied to the motor which is then converted into a mechanical output used to do work on load or even to rotate the turbine for some cases. The fluid power system is more flexible than the mechanical and electrical methods of power generation, and it can generate more than such system of the same size. Fluid systems also give a rapid and accurate responses to the controls. For this reason, fluid power systems are extensively employed in modern aircraft. This power is distributed in the aircraft thru doubled networks, the loads subjected to this method of power generation may include the rudders, ailerons, and elevators which are all grouped as the primary loads(Frazier, 2012). And secondary loads which constitute flaps, slats, airbrake, spoilers and the engine component actuation. Actuators of the fluid system have a high ratio between forces to weight. Nevertheless, their distribution is system has more weight. The hydraulic pipes alone is having about 800 kg. The maintenance of this system is also very expensive since avoidance of leakage is very essential and also the fluids are corrosive and flammable(Helmreich, 2012). The fluid pumps are always driven by mechanical means through the offtake from the variable speed GT spool, the pump is needed to give hydraulic pressure across all speed ranges and will draw energy from the engine even when the actuation is not needed. Even though an electrical power distribution system in the aircraft is lighter than the correspondent fluid power system, the ratio of the power to weight for an electrical power system is much lower than fluid actuators(Hillson, 2016). With the increased fluid pressure of the present airframes of about 500psi for Boeing 787 and also the high efficiency of 85% which is almost to the efficiency of transformers. But still, this fluid power system offers an advantageous power density more than the equivalent electrical power. The ancient fluid systems were controlled by switches of the fluid valves which were employed to control the flow of the hydraulic being driven by a central, regularly driven pump. But nowadays these fluid systems are controlled by some types of actuators known as the conventional linear Actuators (CLA) and some smart fluid sensing actuators which help in sensing and controlling the fluid valve to improve the performance. The figure below shows Distributed Hydrauli c Actuator system diagram The efficiency of pump used in the fluid is very high since it is only driven when the actuation is needed Electro Hydraulic Actuator are in a range of aircraft which includes the flight control operation surface actuation(John, 2015). The figure below shows Electro Hydrostatic Actuator system diagram Electro Mechanical Actuators (EMA) too gives the ability to regenerate onto the electrical bus, though it is not presently permitted. The figure below shows EMA system. Hence in the above types of power generation used in the aircraft, fluid power generation employs mostly the use of flowing liquid to help rotate parts including the turbine which helps to create power. The fluid power generation system uses a lot of pressure pump which helps to push the fluid to the required destination. For the fluid generations, the path in which the fluid is made relatively small so that the speed of the fluid becomes higher hence higher pressure. Mechanical power generation as seen above exclusively uses machines which are rotating and moving through reciprocating movement like the pistons, this help in generation of mechanical power which is highly important in the aircraft. Electrical power makes use of the reaction of chemicals which in deed help in the generation of electrical power. The power generated in electrical can be stored in batteries of the aircraft to help avoid losses and wastage; the energy can be used in lighting among other uses. The efficiency in mechanical is the best followed by fluid and lastly the electrical power. Generated fluid power is transported in the fluid which those of the mechanical are transported fluid and electrical is transported with the help of wires from the point of generation to the point of application. Mechanical power can be used to crate fluid power is then used to rotate rotor parts of aircraft. In the designing of the aircraft power distribution system safety is very paramount and is highly given the care to ensure that accidents which may arise are highly reduced in the aircraft. In the design of the power distribution in the aircraft, we shall capture the prominent characteristics of the optimization of the problem formulation and solution in the power distribution(Poynor, 2015). This design will include an impute filter which is followed by regulated buck converter which is DC- DC converter. The diagram below shows a buck converter The power provided by the aircraft power bus is presumed to be a rigid DC source of Vg=270V. The buck converter is typical of the several power converters usually used in aircraft power system. For the input shown in the figure above, the design variable will comprise the resistors Rd, capacitors C1 and C2, the design also include the three components of inductors. The inductors are presumed to be using typical EE cores. These are defined by set of geometric as shown in the figure below; The values K1 and K2 sown in the figure above are taken to be put, and they signify the ratio of the middle leg and the window correspondingly. From the figure, the bobbin is put in the middle leg of the core(Robert Buck, 2012). The bobbin which has the windings is located around the epicenter leg before the fastened together of the two halves of the EE inductors. The following equation shows inductors L employed as a function the aforementioned physical variables The full set of the input filter in this design is given below, and the variables given include constraints which are related to the windings and wire size and geometry too. Entire weight is the summation of the of the weight of the inductors, resistors, and capacitors which are depicted by the equation below(Ruppert, 2013); The weight of the inductor only is obtained by as the addition of the weight of the copper applied and ferrite used in the windings and the core respectively. This is depicted by the equation below; WL = We +Wcu Where WL = is the total weight of the inductor Wfe= is the weight of the ferrite Wcu= is the weight of cupper The table below shows the design Variables for the Input Filter From the figure above, the weight of copper can be obtained by use of the equation below; And the path of the magnet is given as below; The weight of the capacitors used is estimated as the function of the energy stored in it, and this is given by the below expression(Sheehan, 2016). The constant c was empirically got from the manufacture data sheet which made the design of the electrical power distribution. And lastly, the weight of the resistor which will be used in the design is estimated as a function of the energy dissipated and is obtained mathematically as The measurement of the inductors used in the design must be in a way that optimum acceptable saturation flux density for the ferrite core material BSP = 0.35 T., And this should not be exceeded to help to prevent the inductors core from becoming more saturated(Stephen, 2011). The optimum flux density is obtained as a ratio of optimum flux to cross section area of the middle leg. The specifications givens like the size of the inductors, area of the capacitors, the magnitude of the resistors and the allowance in the inductors make it easy from the design to come up with a good distribution system of electrical power in an aircraft. These specifications should be adhered to and done with care since in the aircraft electrical faults should be reduced since if an accident occur which result to fire or increase in temperature the plane may catch which in turn lead to the fatal accident of the aircraft. The appearance of closed-loop hydraulic systems in the engineering industry was to facilitate those industries requiring extremely high performance. This lead to the use of the hydraulic servo system to be implemented in machine-tool industry. Up to date, they are still being used in these industries for their high performing ability. Recently, the servo system has been gaining a wide application in more varieties of industries(Kern, 2011). These recent industrial applications have been made in automotive testing, material handling, and mining industries. Thereby, the closed-loop servo hydraulic system has increased in its use in and has become a normality in the machine automation industry. The machine automation allows precision, quicker operation, and even simpler adjustment. Other than that, machine automation has enabled the containment of price of machines within acceptable limits. Technology Comparison The servo systems are compared in the light of day to determine the best and highly performing system. The comparison of performance is contested by the electro-pneumatic system and the electro-mechanical servo systems. To come up with high performing actuation system, some major characteristics have to be tested on each system. These compared characteristics are the bandwidth frequency response, resolution and stiffness. They are to be wide, low and stiff respectively to surpass the effective performance required. In aerospace technology, there are some included characteristics that come in mind(Calse, 2014). These are the duty cycle and size and weight minimization. Which are summarized into the following. Cost Weight and size Environment Customer performance Duty cycle Considering all these characteristics required, the electro-hydraulic servo system turns out to be the best in its application in aerospace technology. This is due to the design ability of electro-hydraulic servo system to perform almost all the tasks that have come in place(Kern, 2011). However, the use of electro-pneumatic and electro-mechanical servos is proving to be cheaper in cost than the electro-hydraulic servo systems. This is only so in the range of range of low performance. In the high dynamic response and high power levels, the cost fastly depreciates in these servo systems. Electro-hydraulic servo systems Electro-hydraulic servo systems have some major advantages that they pose in the aerospace industry. They are; Better stiffness characteristics. Wearing rate is low. Simpler and precise work table position control. Faster response to speed and direction control. Among the electro-hydraulic concept, this article discusses the electro-hydraulic actuation (EHA). EHA consists of an electric motor, low displacement pump with low speed; it uses an accumulator and a cylinder as a tank. There is also the need of additional functions, for example, by-pass dumper with safety facilities. To reduce weight, cooler is eliminated but risks EHA failure. This leads to loses. Considering overall efficiency speed control is more important than displacement control. More importantly in ranges of power up to 50% maximum power. However, pump speed control is limited by flow pulsations amplitude leading to special pump design with inner gear concept(Sheehan, 2016). Electro-hydraulic servo configuration The servos output is connected to the transducer to convert it to an electric signal with feedback signal being compared with the command signal. The error that exists is amplified using a regulator and electric power amplifier and input in the control signal going into servo valve. Fluid flowing into the actuator is controlled by servo valve proportioning it to drive current from the power amplifier. The load is then forced to move by the actuator(Poynor, 2015). A signal error is caused by command signal change that makes the load move to prevent the error. A high amplifier gain rapidly and more accurately varies on the command signal. The load can move due to external disturbances. To prevent this, the actuator input is put in opposite direction providing finite error system which is minimized during high amplifier gain. However, the gain has limitations due to stability considerations(Helmreich, 2012). The dynamic pressure feedback is applicable as at low frequencies it works as position feedback. Advantages of Electro-hydraulic system Speed the actuator speed can be realized by various invented methods. These methods include; large pump fitting, use of hydraulic accumulators or use of integral spring pack. These EHA have a manufacturing ability to move valves that require a thrust of up to 900 kg to a distance of 60mm in a duration of 45 ms. The actuator speed, therefore, varies to a great degree even independent of the load or the torque applied. This is contrary to the electro-mechanical devices where the greater the load, the slower the variation of speed(Sheehan, 2016). Accuracy the EHA has a positional accuracy of around 5 microns. This issue to the accurate position control from the hydraulic with almost incompressible hydraulic oil. Generated forces due to the use of almost incompressible oil, there is a reduction in the size of the component for generating great amounts of force. Ultra low power EHA efficiently convert electrical power into useful work with the fitting of a low power position controller. Disadvantages of EHA Any allowable tolerance will lead to higher cost of hydraulic components. With the use of hydraulic fluid, there is upper-temperature limit imposed Conclusion The electrohydraulic systems have high efficiency. The efficiency is applicable in the conversion of electrical energy into useful work(Calse, 2014). The conversion is done to become a linear thrust output or a torque output with high flexibility. The electro-hydraulic systems can be made from a huge range of components evident for actuator formation. Therefore a range of equipment easily meet the standard needed and the special applications. References Billings, C. E. (2012). Aviation automation: the search for a human-centered approach. New Jasey: Lawrence Erlbaum Associates Publishers. Calse, D. (2014). Blast Damage to Air Cleaning Devices (Filter Tests). Tokyo: Western Press. Ean, N. (2013). Rotary Wing Flight. New York: Aviation Supplies Academics. Fallucco, S. J. (2013). Aircraft command techniques: gaining leadership skills to fly the left seat. Delhi: Ashgate. Frazier, D. A. (2012). Training and Instruction. Hull: McGraw-Hill Professional. Helmreich, R. L. (2012). Crew Resource Management. Delhi : Academic Press. Hillson, D. (2016). The Risk Management Handbook in Aviation. Hull: Kogan Page. John, T. (2015). Foundations of Professional Airmanship and Flight Discipline. Chicago: Convergent Performance, LLC. Kern, T. (2011). Flight Discipline. London: McGraw-Hill Professional. Machado, R. (2015). Rod Machado's Instrument Pilot's Handbook. London: Aviation Speakers Bureau. Nagel, D. C. (2015). Human Factors in Aviation. Beijing: Gulf Professional Publishing. Perrow, C. (2011). Normal Accidents: Living with High-Risk Technologies. Chicago: Princeton University Press. Poynor, P. J. (2015). Air Carrier Operations. Chicago: Aviation Supplies Academics. Robert Buck, R. O. (2012). Weather Flying, Fifth Edition. Washington DC: McGraw Hill Professional. Ruppert, M. C. (2013). The Decline of the American Aviation . Amsterdam: New Society Publishers. Sheehan, J. (2016). Business and Corporate Aviation Management, Second Edition. Leicester: McGraw Hill Professional. Stephen, L. (2011). The Playground of Europe in Aviation. Hull: Longmans, Green, and Company.

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.