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THE PRIMARY FUNCTIONAL SYSTEMS — hydraulic, electrical electronic, environmental control, and auxiliary power systems — are separated into localised centres to allow simultaneous inspection and maintenance with minimum congestion between ground personnel and equipment. Other factors considered in the design layout of the service centres were the distribution of components in each system, aircraft weight and balance, component size, area environment and accessibility. Isolation from the hazards of possible engine turbine‐blade and wheel tyre failures was another important consideration. Standardisation and interchangeability of equipment within the L1011 aircraft, and among other transports operating in the same time period also influenced the functional system design.

WITH tailless aeroplanes, all known aerodynamic control devices possess the peculiarity of not only producing moments about one axis, but of also causing secondary moments about one or both of the other axes. Horizontal controllers forming part of the wing near the tips in wings having sweep‐back or sweep‐forward, for instance, do not produce rolling moments alone, when differ‐entially deflected; they also cause yawing and pitching moments. Similarly, wing‐tip disk rudders operated on such wings not only produce yawing moments, but may cause rolling and even pitching moments.

An aeroplane which comprises, in combination, a wing with two spans, a fuselage centrally of said spans, and bracing struts connected to the fuselage and to points on the wing nearer to the centre of each span than to the root and tip thereof, each bracing strut having a substantial lift effect in level flight throughout substantially its whole length, high lift devices of low drag coefficient mounted on each span of the wing, means joined to said devices for controlling both of said devices simultaneously in the same direction, said wing, struts and high lift devices in active position having a combined aspect ratio of at least 15 and a loading of at least 80 kg. per sq. m.

This paper aims to describe a research effort towards the comprehension of the unsteady phenomena due to the deployment of high-lift devices at approach/landing conditions.

The work starts from a preexisting platform based on an immersed boundary (IB) method whose capabilities are extended to study compressible and viscous flows around moving/deforming objects. A hybrid Lagrangian-Eulerian approach is designed to consider the motion of multiple bodies through a fixed Cartesian mesh. That is, the cells’ volumes do not move in space but rather they observe the solid walls crossing themselves. A dynamic discrete forcing makes use of a moving least-square procedure which has been validated by simulating well-known benchmarks available for rigid body motions. Partitioned fluid-structure interactions (FSI) strategies are explored to consider aeroelastic phenomena. A shared platform, between the aerodynamic and the structural solvers, fulfils the loads’ transfer and drives the sequence of the operating steps.

The first part of the results is devoted to a basic two-dimensional study aiming at evaluating the accuracy of the method when simple rigid motions are prescribed. Afterwards, the paper discusses the solution obtained when applying the dynamic IB method to the rigid deployment of a Krueger-flap. The final section discusses the aeroelastic behaviour of a three-element airfoil during its deployment phase. A loose FSI coupling is applied for estimating the possible loads’ downgrade.

The IB surfaces are allowed to move less than one IB-cell size at each time-step de-facto restricting the Courant-Friedrichs-Lewy (CFL) based on the wall velocity to be smaller than unity. The violation of this constraint would impair the explicit character of the method.

The proposed method improves automation in FSI numerical analysis and relaxes the human expertise/effort for meshing the computational domain around complex three-dimensional geometries. The logical consequence is an overall speed-up of the simulation process.

The value of the paper consists in demonstrating the applicability of dynamic IB techniques for studying high-lift devices. In particular, the proposed Cartesian method does not want to compete with body-conforming ones whose accuracy remains generally superior. Rather, the merit of this research is to propose a fast and automatic simulation system as a viable alternative to classic multi-block structured, chimaera or unstructured tools.

THE aerodynamic design of a transport aircraft is fixed by the functions it is intended to fulfil. When the Trident 1 design was begun the aim was to provide a performance that would make it the ultimate subsonic short range jet, able to remain in front‐line service for at least ten years. Maximum effort was therefore concentrated on achieving low drag at high Mach numbers with good handling qualities to match. Comet experience had shown the value of good low speed handling qualities, and so a continuous programme of wind tunnel and flight testing has been carried through to combine the requirements of high Mach number cruising speeds with those of a competitive CLmax. and an acceptable stall pattern, using, as far as possible, relatively simple and well tried high lift devices.

THE shortened runway has become an order of the day. Commercial operators want to offer jet service to communities with small airports. Military services seek to use small, unprepared fields—or no fields at all, just clearings.

The high lift devices are effective at high angle of attack to increase the coefficient of lift by increasing the camber. But it affects the low angle of attack aerodynamic performance by increasing the drag. Hence, they have made as a movable device to deploy only at high angles of attack, which increases the design and installation complexities. This study aims to focus on the comparison of aerodynamic efficiency of different conventional leading edge (LE) slat configurations with simple fixed bioinspired slat design.

This research analyzes the effect of LE slat on aerodynamic performance of CLARK Y airfoil at low and high angles of attack. Different geometrical parameters such as slat chord, cutoff, gap, width and depth of LE slat have been considered for the analysis.

It has been found that the LE slat configuration with slat chord 30% of airfoil chord, forward extension 8% of chord, dip 3% of chord and gap 0.75% of chord gives higher aerodynamic efficiency (C_l/Cd) than other LE slat configurations, but it affects the low angles of attack aerodynamic performance with the deployed condition. Hence, this optimum slat configuration is further modified by closing the gap between LE slat and the main airfoil, which is inspired by the marine mammal’s nose. Thus increases the coefficient of lift at high angles of attack due to better acceleration over the airfoil nose and as well enhances the aerodynamic efficiency at low angles of attack.

The two-dimensional computational analysis has been done for different LE slat’s geometrical parameters at low subsonic speed.

This bio-inspired nose design improves aerodynamic performance and increases the structural strength of aircraft wing compared to the conventional LE slat. This fixed design avoids the complex design and installation difficulties of conventional movable slats.

The findings will have significant impact on the fields of aircraft wing and wind turbine designs, which reduces the design and manufacturing complexities.

Different conventional slat configurations have been analyzed and compared with a simple fixed bioinspired slat nose design at low subsonic speed.

Air connectivity network is an important part of the overall connectivity network of any country. This becomes even more crucial for the interior regions, which have no access to sea routes and have inadequate road and rail connectivity. In India there is uniform distribution of airports throughout the country but only a few of them are currently used because of poor infrastructure availability at these airports. Any aircraft operating from these airports, having minimal infrastructure, need to have efficient high‐lift systems for short takeoff and landing ability as one of the key requirements. The purpose of this paper is look at the performance of a new high‐lift airfoil configuration for application to a general transport aircraft.

The present study deals with two‐dimensional analyses of a high‐lift system for general transport aircraft. The JUMBO2D, a multi‐block structured viscous code has been used to make preliminary analysis of the proposed high‐lift system. The configuration consists of three elements, namely, the main airfoil with nose droop, a vane and a flap.

In the present work the code has been revalidated by computing for NLF (1) 0416 airfoil (clean) and NACA 1410 airfoil with double‐slotted flap. The computed results compare very well with the experimental data. The proposed high‐lift configuration of general transport aircraft has then been analyzed in detail for both takeoff and landing conditions with and without nose droop. The effect of gap between main element and vane on the aerodynamic performance has also been investigated.

This computational study looks at the performance of a new high‐lift airfoil configuration for application to a general transport aircraft.