Rotorcraft Design: The Crucial Influence of Safety from Concept to Fleet Support The 41st Alexander A. Nikolsky Honorary Lecture

It is an immense honor to have been selected to hold the prestigious 41st Nikolsky Lecture and to have the opportunity to synthesize my experiences with regards to the most important principle that permeates aeronautical engineering—“the concept of safety.” Having worked in the rotary-wing field for 39 years, with growing levels of involvement and responsibilities, I have been involved in the design, development, and certification of many helicopter models at the Leonardo Helicopters Division (LHD; formerly Agusta and then AgustaWestland), such as A109, A119, EH101, A129, NH90, AW609. More recently, I had the full responsibility of design, development, certification, and entry into service of three new helicopter types within the “AW Family concept”, specifically the AW139, AW189, and AW169. I am profoundly grateful for the mentors encountered in my professional life—Bruno Lovera and Santino Pancotti, both of whom were also honored with the Nikolsky Lectureship. In working with them, not a single day passed where the word “safety” was not mentioned. They taught me that “safety” shall be the mantra of every aeronautical engineer because it is our principal duty and responsibility, towards those who travel in, work on, and work with our products and entrust their lives to our work and professionalism daily. I have tried hard never to forget this lesson, and to convey this to the young engineers that I have had the chance and pleasure to work with. If I have been able to pass on this lesson successfully, through my work with others through this lectureship, it would be the greatest achievement of my life. In this vein, this paper is organized in three parts: (i) definitions and principles, along with some “philosophical” concepts; (ii) the application of these principles at Leonardo in the design of the latest generation of helicopters, and finally (iii) a discussion of emerging “safety technologies” that promise to improve the safety of future helicopters and operations.

Unspoken Modernity: Bamboo-Reinforced Concrete, China 1901-40

Engineering science in the China of 1901-40 had unique characteristics that disrupt the idea of a universal approach to its history.1 The following case study describes the ideas and trials of introducing bamboo into the seemingly globalised technology of reinforced concrete—an innovation developed across the borders of mechanical, naval, civil, and aeronautical engineering. The article showcases a way of knowing and working by twentieth century engineers that has not been fully acknowledged, and is not only a phenomenon of China. While bamboo was a complicated and somewhat marginal object for engineering, it did make the European concrete technology more viable in the construction sites of China, and stimulate engineers’ experimental and resourceful spirit in mobilising both craft and scientific knowledge. It also opened up a challenge to engineering science of the time.

MECHANICAL CHARACTERISTICS OF REINFORCED AND THREE-LAYER SHELLS BASED ON METAMATERIALS, TAKING INTO ACCOUNT OPERATIONAL DAMAGE

Abstract— The conventional design in aeronautical engineering is reinforced shell, which for most structures is a thin shell with a stringer set. This article compares the behavior of a conventional reinforced shell and a spaced shell metamaterial structure with a reinforced set using the example of a main airplane pressure bulkhead. The evaluation criterion is to ensure the required level of residual strength when the limiting state is reached.

Computational experiment of the thin-film electroluminescent display devices applicability in aviation

The development of methods and means of testing the applicability of thin-film electroluminescent indicator devices as displays in aircraft is carried out. Thin-film electroluminescent displays are used in equipment and systems that require high image quality and reliability, as well as a long service life of the devices. The result of the performed work is the ExpAT program, which allows to carry out a computational experiment to test of the applicability of the TFEL indicator devices in aeronautical engineering. As a result of the computational experiment, variants of structures of thin-film emitting structures that meet the operating conditions of indicators in avionics are shown.

Research on Aerofoil Shape to Increase the Effectiveness of Aeroplanes

In the modern era where emphasis on air travels is increasing day by day. There is no near alternative of jet fuel. In such situation where fossil fuel use becomes bounded than, we should try to increase efficiency from available resources so as to push world towards sustainable development. Efficiency of aeroplanes greatly depends on couple of major factors like load carried, type of fuel used, power of engine installed, etc. But if we take similar aircrafts with similar loads than one criterion plays pivotal role in efficiency of aircrafts and that is shape of aerofoil wings. Angle of attack also depends on this. Optimum shape of aerofoil has always been topic of research for engineers. In present paper, an aerofoil shape with bottom surface backlash is analysed in ABAQUS software. Different modes of failure help in better designing as well as maximum bearable load by aerofoil shape. Keyword: 1. Aeronautical engineering, 2. Fluid Mechanics, 3. Analysis on ABAQUS, 4. Computational fluid dynamics.

Experimental evaluation of mechanical properties of friction welded mild steel

Friction welding is a solid state joining process used to join similar and dissimilar metals, not possible with other available welding techniques. Now a day’s Friction welding is most commonly used in industry that is aeronautical engineering, automobile engineering, submarine industry and heavy industry. In this research, an experimental setup was designed and fabricated in order to accomplish friction welded joints mild steel. Thereafter, the effect of forging pressures and rotation speed on the mechanical properties of friction welded ST 42 steels, produced by mechanical joining, have been investigated. Samples were welded under friction pressure 10 MPa by different forging pressures 25 MPa and 35 MPa with different rotation speed 1095 rpm, 1200 rpm, and 1400 rpm. The tensile strength values of the weldments were determined and evaluated. The top result is produced from sample were welded under forging pressures 35 MPa at rotation speed 1400 rpm that is tensile strength 437,27 N/mm2 and yield strength 399,75 N/mm2.Keywords : friction welding, forging pressure, tensile strength, yield strength, and elongation.

Experimental study on the effect of bionic flap parameters on airfoil aerodynamic performance

The effects of bionic flap on airfoil performance were experimentally studied to provide theoretical support for the application of the bionic flap in aeronautical engineering. Seven kinds of bionic flaps were used to study the effects of the key flap parameters, including the flap angle, length, shape, and position, at a Reynolds number of Re = 0.8 × 106. At small angle of attacks (AoAs), the drag and pitching moment increased and the lift reduced when using the bionic flap. While at high AoAs, the lift increased and the drag reduced, which improved the airfoil stall characteristics. The configuration of deflection bionic flap had the smallest initial AoA for improving the airfoil stall characteristics in the seven kinds of bionic flaps. More than eight degrees of the effective AoA range for improving lift characteristics could be achieved. The maximum lift coefficient could be increased by 3.9%. Additionally, the control mechanisms of the flap under different flow conditions (attached flow and separated flow) were deeply studied. In the attached flow, the effective camber and thickness of the basic airfoil could be changed by the flap, resulting that the flow around the airfoil was affected, which in turn affected the Cl and the slope of the lift line. In the separated flow, the flap affected the flow around the airfoil by controlling the development of the trailing edge separation vortex. These research results confirmed the aerodynamic mechanisms for the formation of double layered feathers when birds land, and provided insight into application of bionic flaps in aeronautical engineering.

Equipment Condition’s Effect on Student Perceived Workload and Efficiency of Problem Based Projects in an Aeronautical Engineering Technology Program

Aeronautical Engineering Technology (AET) of Purdue University’s School of Aviation and Transportation Technology offers its students a comprehensive and holistic approach to engineering in an applied fashion. Students’ learning outcome includes an application of technical knowledge and hands-on skills in areas of aerospace design, operations, and manufacturing. The curriculum of the program includes a course in which students must learn advanced maintenance concepts and practices including the overhaul of reciprocating engines. This study examined the relationship between engine operational vs. non-operational statuses, time spent to finish a task, and student perceived workloads regarding the maintenance procedures. The tests followed the Federal Aviation Administration (FAA) requirements for the practical test questions from the Airframe and Powerplant Certificate (A&P) Exam. Students were also required to fill out a task perceived load index developed and used by NASA.