Certain Type Of Aircraft Research Articles

A Flight Test Method of Flammable Liquid Leakage and Discharge for Certain Aircraft

To guarantee the successful completion of airworthiness certification test for a certain type of aircraft, the leakage and discharge compliance criteria of flammable liquid were designed by studying airworthiness requirements and the design characteristic of the civil aircraft, where flammable liquid leakage zones and hazardous zones in which liquids are not allowed to enter were determined. Further the test equipments and the dyeing liquor for replacing flammable fluid were developed, and ground and flight test methods were proposed. Moreover, the above test equipment and methods were applied to flight tests of flammable liquid leakage and discharge for certain civil aircraft. The test results show that the test equipment is stable and reliable, and the flight test method can accurately demonstrate the flammable liquid leakage and discharge.

INVESTIGATION OF STRESSES IN TURBINE ENGINE DISC

In this paper, the failure analysis of the air engine's turbine disk has been established in a certain type of aircraft. From the visual examination of the surface of the fracture, the signs of the beach could be inspected, general of fatigue failure. In operating conditions, a non-linear finite element was used to determine the stress position of the disk / blade segment. High stress areaswere found in the area of lower fur-tree slots, where the failure occurred. A calculation was also done at a very rotational pace.The focus of this study is devoted to the mechanism of damage to turbine discs and significant high stress areas.Residual stressesthat after removing the root cause of stress, it remains in solid content. Under residual stress engineering environmental andaircraft load challenges, increasingly important aspects of design and construction of monolithic wind farms are becomingincreasingly important. Residual force does not affect structural performance only during the life cycle of the service, but theyalso affect the quality of the part during manufacturing and assembly. Residual stress can be desirable or undesirable, duringmost of the manufacturing processes related to physical deformation, heat treatment, machining or processing operation, residual stress occurs, which change the size or properties of the material. They have originated from many sources and can be present in unused raw materials produced during production or manufacture by in-service shipment.

Scheduling aircraft take-offs and landings on interdependent and heterogeneous runways

This paper presents an optimization method for the aircraft scheduling problem with general runway configurations. Take-offs and landings have to be assigned to a runway and a time while meeting the sequence-dependent separation requirements and minimizing the costs incurred by delays. Some runways can be used only for take-offs, landings, or certain types of aircraft while schedules for interdependent runways have to consider additional diagonal separation constraints.Our dynamic programming approach solves realistic problem instances to optimality within short computation times. In addition, we propose a rolling planning horizon heuristic for large instances that returns close-to-optimal results.

Scheduling Aircraft Take-Offs and Landings on Interdependent and Heterogeneous Runways

This paper presents an optimization method for the aircraft scheduling problem with general runway configurations. Take-offs and landings have to be assigned to a runway and a time while meeting the sequence-dependent separation requirements and minimizing the costs incurred by delays. Some runways can be used only for take-offs, landings, or certain types of aircraft while schedules for interdependent runways have to consider additional diagonal separation constraints.Our dynamic programming approach solves realistic problem instances to optimality within short computation times. In addition, we propose a rolling planning horizon heuristic for large instances that returns close-to-optimal results.

<i>In Situ</i> Tester Research and Development of Control Stick Force Sensor

Based on the practical need for control stick force sensor test of a certain type of aircraft, corresponding design method of control stick force sensor tester is propoesd, its basic testing principle and course are analyzed,in th end this type of tester is made and tested practically.The result shows that the control stick force sensor tester possesses the characteristics of easy manipulation, perfect function, high intelligence,fast and exact test, provides a scientific testing means for the performance of aircraft control stick force sensor,and has a good application value and popularizing prospect.

Analysis on the Error of Fire Control Measuring Equipment of a Certain Type of Aircraft

The fire control measuring equipment are the most important devices when the aircraft attacks, so its precision directly affects the final outcome. In this paper, the tracking and measuring errors of measuring equipment of fire control calculator of a certain type of aircraft are studied, the error sources in the process of aircraft tracking and attacking are analyzed and simulated, the influences of each errors sources on tracking and attacking error are discussed, and some advises for reducing errors are given

Design and Realization of the Small Power Two-Way DC Power Supply Based on UCC2800

To provide DC power to auxiliary equipment for a certain type of aircraft, according to the actual need, small power two-way dc power supply is designed using current mode pulse width modulator UCC2800. This paper introduces the basic principle of UCC2800, and also introduces the design and realization process of the low-power dc power supply based on UCC2800.

Research on the Control Principle of Aircraft AC Starter/Generator

AC starter/generator is a new starting/generation dual-function technology applied to the aircraft. The previous pneumatic starter, brushed DC starter/generator or DC starter are replaced by the synchronous AC motor, thereby reducing the weight of airborne equipment effectively. Based on AC starter/generator driven by auxiliary power unit (APU) used on a certain type of aircraft, this paper mainly carries out the research on the composition of AC starter/generator system, starting process and its control principle, as well as demonstrates how the starting torque is controlled. Theoretical study shows that the torque can be precisely controlled through the control of the torque component of stator current when the rotor field oriented vector control strategy is adopted.

Static Strength Analysis of Components of Flap Control System for a Certain Type of Aircraft

Pull rod and rocker arm are important parts of aircraft control system, its strength, stiffness and stability can largely affect the aircrafts control effect, sometimes the flight safety will be influenced [2]. A type of aircraft control system has been upgraded and modified, therefore the pull rod and rocker arm of the flap control system need to take the static strength test. Based on field test and finite element simulation analysis, this paper has the static strength of pull rod and rocker arm checked, and to verify the correctness of the finite element model and lay foundation for the optimization design of components of aircraft control system.

The Monitoring Elements Structure of Process of Requirement Integrated & Dynamic Espial for Complex Products RMS

Aiming at the disadvantages of traditional process of achieving the RMS requirements, which the less of monitoring points, hardly controlling this process and easily leading to the iterative design, etc. are included. A methodology, Process of Requirement Integrated & Dynamic Espial (PRIDE), for the achievement of equipment RMS requirements was proposed at first, and its framework was given subsequently. Then a set of elements structure of PRIDE, based on the monitoring space model of the overall system, overall process and overall properties (three-A), was built, which lay the foundation for the realization of the PRIDE in achieving equipment RMS requirements. Finally, a certain type of aircraft was taken as the case to verify the feasibility of the monitoring elements structure.

Semiquantitative SDG Graphical Modeling for Complex System Fault Diagnosis

For the shortcomings of existing SDG modeling methods in fault diagnosis, a data-driven semi-quantitative SDG automatic graphical modeling approach and a direct manual SDG graphical modeling approach are investigated. Function failure analysis procedures and data modeling process based on system principle are introduced in detail, and relevant graphical modeling tool are developed. A fault diagnosis modeling for the air supply system of certain type of aircraft is taken as an illustration to verify the validity of proposed modeling method.

Patient Safety as the Number One Priority in Healthcare Design

Over the past few decades, healthcare has become increasingly more complex, difficult to coordinate among multiple providers, heavily impacted by technology, and subject to situations and conditions that have the potential to diminish quality or breach patient safety. Patients come to hospitals in their most vulnerable state-often in pain, usually fearful, and always feeling a bit out of place. How can this be? Hospitals are supposed to be a safe haven and a place of healing and rest; yet many patients are victims of errors in treatment, procedure, or medication, or they are injured by elements of the hospital environment. A hospital can be a dangerous place for patients because its unfamiliar environment contrasts with home (Tzeng & Yin, 2008a). As designers and healthcare professionals, what can we do to design a healthcare facility that minimizes the potential for risk and enhances patient safety?Although there are many claims that specific design features reduce medication errors, decrease patient falls, lessen cross-contamination, and improve patient safety outcomes, disseminated evidence to support the direct relationship between specific design features and patient outcomes has been sparse. This issue of HERD focuses on patient safety in healthcare design with the intent of adding to a body of knowledge about the relationships between the built environment and patient safety outcomes. I am excited about this issue and fully believe that we will see more research demonstrating the effects of design features on patient safety outcomes that will guide future design decisions. Patient safety should be the number one priority when evaluating the efficacy of design alternatives, and we have unprecedented opportunities to affect quality and patient safety by creating safer work environments for professional staff and safer care environments for patients.A Multidisciplinary ApproachReducing patient risk by means of facility design requires a multidisciplinary approach, because each discipline brings a body of knowledge, viewpoints, preferences, and interpretations to the table to expose hidden assumptions about what could make a difference in ensuring patient safety (Reiling, 2006; Wears, Perry, & Sutcliffe, 2005). We do not often think of safety as a science, yet it is a science with its own body of knowledge, research, and vested academic degrees. According to Wears, When the patient safety movement first began, an important early insight was the realization that a great deal was already known about the problem of safety in complex socio-technical systems based on years of research and practice in a wide variety of (p. 4). Many lessons have been learned from the space program, aviation, the military, and the nuclear power industry that can and have directly influenced assumptions about safety in healthcare design. The same-handed room design concept is one example of borrowing safety knowledge from the aviation field, where all cockpits in certain types of aircraft are designed identically to reduce the potential for pilot confusion and error. Some have accepted this idea as evidence that can be applied to healthcare design (Reiling, 2006).Human factors science applies what is known about human capabilities and limitations to the design of systems, processes, and environments to maximize human potential in the environment and reduce the potential for stress, strains, and errors. Applying human factors science to the healthcare setting, the user (patient) interface with a design would be studied in detail and tested to determine requirements for the built environment that would ensure patient safety (Blanchard & Fabrycky, 1998; Wickens, Lee, Liu, & Gordon Becker, 2004). Some of the research methodologies that could be used as human factors evaluation methods might include: (1) focus groups with patients and providers to identify potential risk areas for patients; (2) ethnography to understand the real-world or lived experience of patients in the healthcare environment; (3) iterative design processes, with each design evaluated in relation to patient safety priorities; and (4) systematic task analysis to evaluate human interaction with the environment under specified conditions (patients with different conditions in specific situations). …

Cognitive function following reported exposure to contaminated air on commercial aircraft: methodological considerations for future researchers

Cabin air on commercial aircraft is sometimes contaminated with jet engine oils containing organophosphates (OP). Aircrew have complained of chronic ill health and cognitive impairment following exposure to contaminated air, but a debate is ongoing about causation, diagnosis and treatment of long-term effects. The incidence of contaminated air events is difficult to quantify, as commercial aircraft do not have air quality monitoring systems on board. According to statistical records, certain types of aircraft suffer more fume events than others (e.g. the BAe 146 and Boeing 757) and it has been suggested that airframe may serve as a proxy measure of exposure. The current study sought to investigate this claim, and to determine whether an association exists between exposure to contaminated air and neuropsychological impairment. Twenty-nine pilots were recruited and split into two exposure groups according to aircraft type flown, but few differences were noted between groups in terms of exposure history or cognitive function. Pilots’ profile of cognitive performance deviates from that seen in the normal population, but mirrors that seen in other OP-exposed cohorts. In particular they show decrements in performance on tests of attention, psychomotor speed and visual sequencing. Given the safety implications of these findings, further research is warranted.

Simulation of Gravity Feed Fuel for Aeroplane

Gravity feed is one fuel supply way for aeroplane and the simulation of it is very important. The traditional method to calculate the gravity feed is to assume that only one tank in fuel system supplies the needed fuel to the engine, and then calculated for the single branch. Actually, all fuel tanks compete for supplying fuel and the key problem for gravity feed calculation is to simulate the multiple-branch and transient process. The present paper gives the mathematical model for fuel flow pipe, pump, check valve and the simulation model for fuel tank at first, and then presented a new calculation model for gravity feed fuel of aeroplane fuel system based on the flow network theory and time difference method. The model takes into consideration all fuel tanks and can solve the multiple-branch and transient process of gravity feed. Finally, the thesis gives a numerical example for a certain type of aircraft, achieved the variations of fuel level and flow mass per second of each fuel tanks, the variations of the fuel pressure at the engine inlet, and predicted the maximum time that the aeroplane could fly safely under gravity feed. The numerical example indicts that the method proposed here is intrinsically superior to the traditional methods and is closer to understanding the real seriousness of the fuel supply situation.

Improving Aircraft Endurance Through Turbulent Separation Control by Pulsed Blowing

Boundary-layer unsteady blowing is one of the most advanced solutions for reducing aircraft parasite drags and flow separation at high angles of attack. It allows high lift along with low drag to be achieved and, because endurance is one of the most important performance parameters for certain types of aircraft, such as unmanned aerial vehicles, clearly the CL 3/2 /CD ratio has to be maximized. The main goal of the present investigation is to explore possible ways to obtain efficient turbulent boundary-layer control and, at the same time, to consider the practical problems connected to the installation of the device in a real wing. This study seeks mainly to verify the effectiveness of active control via pulsed blowing as a tool to delay boundary-layer separation. Numerical simulations and wind-tunnel experimental investigations on a wing model equipped with instruments are presented and the results discussed. An extensive numerical and experimental investigation on the parameters that can affect flow separation has been carried out. As a result of this analysis, it seems that tubing length produces the most significant effect on the resonant frequencies of a pulsed-blowing system, whereas slot exit and cavity volume mainly affect the resonant peak amplitude. The best actuation frequency varies, depending on the type of aerodynamic performance to be optimized (efficiency, lift, or endurance).

Novel approach for determining the optimal axial preload of a simulating rotary table spindle system

This paper presents a new theoretical model to determine the optimal axial preload of a spindle system, for challenging the traditional method which relies heavily on experience of engineers. The axial preloading stiffness was treated as the sum of the spindle modal stiffness and the framework elastic stiffness, based on a novel concept that magnitude of preloads can be controlled by measuring the resonant frequency of a spindle system. By employing an example of a certain type of aircraft simulating rotary table, the modal stiffness was measured on the Agilent 35670A Dynamic Signal Analyzer by experimental modal analysis. The equivalent elastic stiffness was simulated by both finite element analysis in ANSYS® and a curve fitting in MATLAB®. Results showed that the static preloading stiffness of the spindle was 7.2125 × 107 N/m, and that the optimal preloading force was 120.0848 N. Practical application proved the feasibility of our method.

Failure analysis of turbine disc of an aero engine

This paper presents the failure analysis of the turbine disc of an aero engine, installed in a certain type of aircraft. From the visual examination of the fractured surface, it was possible to observe beach marks, typical of fatigue failure. A non-linear finite element method was utilized to determine the stress state of the disc/blade segment under operating conditions. High stress zones were found at the region of the lower fir-tree slot, where the failure occurred. A computation were also performed with excessive rotational speed. Attention of this study is devoted to the mechanisms of damage of the turbine disc and also the critical high stress areas.

Aircraft noise modelling for environmental assessment around airports

Various models for predicting aircraft noise around airports are described. Improved acoustic models of aircraft are formed by summing models for the noise sources peculiar to each of the aircraft types. The concept of “noise radius” has been formulated and implemented as a useful alternative to the conventional noise–power–distance relationship. Trajectory noise models have been used to analyse the influence of various operational factors on noise levels. The main procedure for assessment of aircraft noise around an airport is in accordance with the international requirements but each component has been derived in a particular way. Results of noise predictions for certain types of aircraft are presented. Atmospheric conditions are predicted to have an important influence.

Line Transect Estimators for Left-Truncated Distributions

Left-truncated line transect data sets may occur when surveying with certain types of aircraft where the observer cannot look straight down. A general model of left-truncation in line transect sampling is developed and parametric estimators are derived in such cases when the underlying distribution of right-angle distances is either exponentially or half-normally distributed. Computer simulations demonstrate the validity of the derived estimators and the expected nonrobustness against alternative distributions. An aerial survey example using dolphin data is presented.

Airports, noise and town planning

Airports and airways around airports have until now produced more and more noise affecting people living in the vicinity. In order to solve this problem, or at last relieve the disturbances, airports have been located further and further away from city centres, and aircraft movements around airports have been more and more restricted to narrow airways. I think this way is a cul-de-sac. You cannot go on forever producing more and more noise and moving airports further and further away. Neither can you abandon ever-larger built-up areas because the air traffic development makes them unsuitable for living. And certainly you cannot alter the human way of reacting to stress--what remains is to construct aircraft producing less noise. Around each airport there ought to be established a demarcation boundary outside which air traffic will not be allowed to cause more than clearly defined noise values. If these values wre exceeded, traffic has to be cut down or certain types of aircraft have to be prohibited. Airports are likely to have a noticeable effect on the physical structure of a region. Therefore, the location of airports should be determined as a function of the desired regional structure. The following principle for siing an airport can be derived from the experience with Arlanda. If one wants to (a) make the most of the sites with good communication possibilities near an airport; and (b) make full use of the communication system established between the city centre and the airport, the corridor between the two should be developed extensively. But to do so, it is imperative to restrict flight-noise disturbances in this corridor. The best way of achieving this seems to be by placing the runway directions at the airport perpendicular to the direction of the corridor.