Delta Wing Aircraft Research Articles

Aerodynamic characteristics of a delta wing aircraft under ground effect

The main objective of this study is to investigate the impact of ground effects on the aerodynamic coefficients of a delta wing aircraft model. Since the flow on the delta wing exhibits vortical flow inherently, it is crucial to examine the influence of ground effects under these conditions. An experimental study was conducted to enhance understanding of the aerodynamic behavior of an aircraft model incorporating a delta wing-body-vertical tail. Experiments were conducted in a subsonic wind tunnel with a test section measuring 2.8 m × 2.2 m. Measurements were taken using a sting type balance to determine the aerodynamic forces and moments. All experimental tests were performed at a Reynolds number of 1.5 × 106, with the specific aim of examining and identifying the influence of the ground on aerodynamic coefficients. To investigate how ground effect affects the aerodynamic performance of the model, a fixed plate with an adjustable height was placed underneath it. The distance between the model and the ground was varied, and resulting data indicated that increased proximity to the ground improved longitudinal static stability. The results revealed that the presence of the ground plane resulted in a 6% increase in the maximum lift coefficient. Meanwhile, the lift increases around 25% due to ground effects at an angle of attack of 14° as it approaches the ground. The lift coefficient was enhanced across all angles of attack, while the induced drag coefficient decreased, resulting in an overall increase in aerodynamic efficiency. The lift curve slope saw a 16.9% increase when the model’s height from the ground plane was less than half of the wing span. As the height decreased further, the aerodynamic center shifted backward, leading to an increase in longitudinal static stability. The rolling moment and yawing moment coefficients becomes unstable at angles of attack above 30°.

Nonlinear Aerodynamic Modeling of Cascade Fins And Delta-Wing Aircraft Model

The paper presents the modeling of the nonlinear longitudinal aerodynamics associated with the cascade fins and scale-down model of a delta-wing aircraft at high angles of attack. The Kirchhoff’s steady-state stall model was used to model the stall characteristics and the Maximum Likelihood (ML) method was used to estimate the stall characteristic parameters. The cascade fin models with a rectangular and an airfoil (NACA-0012) cross-section were used to generate the variation of lift coefficient with angle of attack. The wind tunnel data pertaining to the cascade fin models were generated by varying the gap-to-chord ratios with and without end plates. The effect of end plates and the gap-to-chord ratio on the stall characteristics and the parameter estimation was analysed. The estimation results were compared to the reference results. In addition, the application of the Kirchhoffs steady-stall model to the scale-down model of a delta-wing aircraft has also been presented. The analysis pertaining to the cascade fins can be utilized as a basis for an initial design of cascade fins for guided missiles with desirable stall characteristics.

FLOW ANALYSIS ON DELTA WING – A REVIEW

Many aircraft, like fighters and bombers, are delta-winged aircraft. These aircraft have the characteristics of producing a greater lift at very small angles of attack even at very low Reynold’s number. Highly swept-wing aircraft experience greater lift due to the generation of the leading-edge vortex at a high angle of attack flight. The phenomena of vortex breakdown are noticed which leads to the reduction of the vortex lift and leads to the instability of the aircraft. This paper deals with an analysis of the flow on the delta wing with the existing literature and compares its benefits over the conventional wings using experimental and computational methods. The critical angles, pressure, and velocity variations are observed along with chord and spanwise locations.

Emergency Power Generation Studies for various Stores Configurations of a Tail Less Delta Wing Aircraft

Emergency Power Generation Studies for various Stores Configurations of a Tail Less Delta Wing Aircraft

Finite-Time Control of Wing-Rock Motion for Delta Wing Aircraft Based on Whale-Optimization Algorithm

The rise of wing-rock motion in delta-wing aircraft has an adverse effect on the manoeuvrability of aircraft and it may result in its crash. This study presents a finite-time control design to tackle the dynamic motion due to the Wing-Rock effect in delta-wing aircraft. The control design is developed based on the methodology of Super Twisting Sliding Mode Control (STSMC). The Lyapunov stability analysis has been pursued to ensure asymptotic convergence of errors and to determine the finite time. The design of STSMC leads to the appearance of design parameters, which have a direct impact on the dynamic performance of the controlled system. To avoid the conventional tuning of these parameters and to have an optimal performance of the proposed controller, a modern optimization technique has been proposed based on Wale Optimization Algorithm. A comparison study between optimal and non-optimal finite-time super twisting sliding mode controllers has been established and their effectiveness has been verified via numerical simulation using MATLAB programming format.

Aspek Fisika dalam Perancangan Pesawat Aeromodeling Jenis Delta Wing

The Delta Wing aeromodeling aircraft uses a symmetrical airfoil where the top of the wing is the same as the bottom. The main aspects in the design of the Delta Wing aircraft are center of gravity, the engine thrust, the air resistance, the lift and the weight. Delta Wing aircraft are dominated by jet-engined aircraft with the advantages of high speed and small air resistance. From the design and field trials, it was concluded that the minimum thrust of the Delta Win aircraft must be equal to 2 times the total weight of the aircraft so that the aircraft is able to maneuver vertically, perform looping maneuvers, roll maneuvers and hovering.

Model Reference Adaptive Control of Switched Dynamical Systems with Applications to Aerial Robotics

This paper presents an adaptive control law for unknown nonlinear switched plants that must follow the trajectory of user-defined linear switched reference models. The effectiveness of the proposed control architecture is proven in two alternative frameworks, that is, analyzing Caratheodory and Filippov solutions of discontinuous differential equations. Numerical and experimental data verify the applicability of the theoretical results to problems of practical interest. The proposed numerical simulation involves the design of a model reference adaptive control law to regulate the roll dynamics of a reconfigurable delta-wing aircraft. The proposed flight tests involve an aerial robot tasked with autonomously mounting a camera of unknown inertial properties to a vertical surface.

Composite adaptive posicast controller for the wing rock phenomenon in a delta-wing aircraft

The nonlinear dynamic phenomenon like wing rock is one of the important issues in the high performance aircraft autopilot design. This phenomenon occurs in the form of constant amplitude oscillations in the roll dynamics, during the flight at high angles of attack (AOAs) and endangers carrying out the mission of an aircraft. In this paper, a composite adaptive posicast controller is designed for the wing rock phenomenon in a delta-wing aircraft with known input delay. The existence of the input delay besides the parametric uncertainties of the system dynamics adds to the complexity of the problem and can cause undesirable troubles in regulation and tracking performance or instability in the control system. Consequently, there is a need for a controller that can provide the stability and desirable regulation and tracking for the system. The proposed control method uses the system state forecasting and the composite model reference adaptive controller in an integrated control structure based on linear quadratic regulator (LQR). Combining the tracking error and the prediction error to form the adaptive laws in the composite model reference adaptive controller improves the characteristics of the system response and provides a better performance compared to the model reference adaptive controller in which the adaptive laws are formed only with the tracking error. Simulation results show the efficiency of the composite adaptive posicast controller in counteracting the system uncertainties in the presence of considerably large input delay cases.

Magnetic Suspension of a Moving Aircraft Model at High Angles of Attack

The magnetic suspension and balance system (MSBS) suspends a model without physical support systems. With the use of a pair of two-dimensional CMOS image sensors, a position sensing system that detects the position of the model by dynamically tracking the model attitude was developed with the aim of applying an MSBS for high angles of attack (AOAs). The position sensing system developed in this study was able to detect the position and attitude of the model within the range of AOAs of -40 to 40 degrees. The position sensing system was installed to an existing 60 cm MSBS at JAXA, and static and dynamic wind tunnel tests were conducted to investigate the ability of the MSBS and the dynamic characteristics of a delta wing aircraft model at various AOAs. The MSBS could suspend and oscillate the model in pitch direction at AOA of 15 degrees with the amplitude of 6 degrees in the wind. The delta wing model was dynamically stable at each tested AOAs.

Convertible delta-wing aircraft for teaching and research

Abstract This paper presents our initiative on the design and building of a convertible aircraft for fault tolerant control. The main advantage of convertible over conventional aircraft is that they can take-off and land vertically, practically eliminating the need for a long runway. At the same time, fixed wings allow to improve energy efficiency with respect to multi-copters. To satisfy these objectives, we have chosen a bi-rotor delta-wing design which is described in the first part of the paper. The paper gives a description of the main educational activities of this project emphasizing its multidisciplinary nature. Indeed, one important aspect of this project is that we have had the chance to work with students from various specialities (such as mechanical engineering, embedded systems, avionics and automatic control) on bachelor and master’s levels. Moreover, the end result of this project should provide us with a very interesting experimental test-bench for teaching and research purposes. Finally, this activity is also the opportunity for our students to develop their soft skills such as project management and communication.

Sensor Anomaly Detection and Recovery in the Roll Dynamics of a Delta-Wing Aircraft via Monte Carlo and Maximum Likelihood Methods

This paper studies the problem of sensor anomaly detection, estimation and recovery for the roll dynamic model of a generic delta-wing aircraft. The proposed algorithm employs particle filtering and maximum likelihood methods to detect and estimate the anomaly. The estimated anomaly is then used to correct the sensor readings. It is assumed that both the system model and sensor outputs are corrupted by noise, which are not necessarily Gaussian. Simulation results are presented to show the performance of the proposed algorithm.

Optimal LQR Controller Design for Wing Rock Motion Control in Delta wing Aircraft

In this work, an Optimal Linear Quadratic (LQR) and optimal Minimax controller is proposed for Wing Rock Motion Control in Delta wing Aircraft model. The nonlinear Wing Rock Motion dynamics were considered. The LQR and Minimax controllers are designed in order to reduce the Wing Rock Motion. Simulations are performed in order to verify the ability of both controllers to reduce the wing rock motion in delta wing aircraft. Results were plotted together in order to show the difference of performance for both controllers for a comparative point of view.

Topological structures of vortex flow on a flying wing aircraft, controlled by a nanosecond pulse discharge plasma actuator

Vortex control is a thriving research area, particularly in relation to flying wing or delta wing aircraft. This paper presents the topological structures of vortex flow on a flying wing aircraft controlled by a nanosecond plasma dielectric barrier discharge actuator. Experiments, including oil flow visualization and two-dimensional particle image velocimetry (PIV), were conducted in a wind tunnel with a Reynolds number of 0.5 × 106. Both oil and PIV results show that the vortex can be controlled. Oil topological structures on the aircraft surface coincide with spatial PIV flow structures. Both indicate vortex convergence and enhancement when the plasma discharge is switched on, leading to a reduced region of separated flow.

Multiple model adaptive control using second level adaptation for a delta-wing aircraft

Purpose – The purpose of this paper is to design a stable controller such that the control input is applied to the delta-wing aircraft in order to adjust the roll dynamics. The controller must provide a desired tracking performance with minimum tracking error. Design/methodology/approach – In this paper, the second level adaptation (SLA) strategy is applied to control a delta-wing aircraft using multiple models. The implemented control structure is compared with the first level adaptation (FLA) and model reference adaptive control (MRAC) techniques. Findings – SLA architecture not only copes with a wide uncertainty domain caused by aerodynamic effects, but also its rapid and accurate convergence is one of its most important features. Furthermore, this strategy makes a smoother control signal with respect to FLA and MRAC even at the same initial times. It should be also noted that SLA using three models, copes with uncertainty that may occur to the aircraft at high Angle Of Attacks (AOAs) at the entire flight envelope. Originality/value – In this paper for the first time the application of this strategy is used to identify and control a delta-wing aircraft. Furthermore a systematic block diagram approach is proposed for the design.

Numerical Investigation of the Aerodynamics of a Delta Wing in Ground Effect

The aerodynamics of a delta-wing aircraft is influenced by the ground effect during takeoff and landing. In this paper, the ground effect of a sharp leading-edge delta wing with sweep angle of 65 deg is investigated by using ANSYS Fluent employing the unsteady compressible Reynolds-averaged Navier–Stokes equations and the shear-stress transport turbulence model. The angle of attack is fixed at 20 deg and the flight height is varied from high altitude to close proximity to the ground. The lift, drag, and nose-down moment increase with decreasing flight height, and the major contribution to the variation in aerodynamic forces comes from the windward side of the wing. In ground effect, the pressure under the delta wing increases due to the “ramping” effect, the strength of the leading-edge vortex enhances before breakdown, and the vortex breakdown is promoted due to the increased adverse pressure gradient.

Dynamic Landing Response Analysis of a Flexible Tailless Delta Wing Aircraft

Modern tailless delta wing aircraft is built for high performance with light weight leading to structural flexibility. During landing, high vertical sink rate of aircraft causes peak transient loads in and around the landing gear attachment locations. These reactions forms the load cases for local sizing of airframe and its responses determine the overall integrity. This paper describes the co-simulation approach to carry out the dynamic landing analysis on a flexible tailless delta wing aircraft and examines the responses at certain critical locations such as the tip of wings, fin and nose for nominal landing conditions. The reactions are obtained from the Landing gear supplier through MSC Adams multi-body dynamic simulation of full aircraft with non-linear stiffness and damping models of Nose and Main landing gear systems. The landing response analysis is carried out on a flexible aircraft using industry standard MSC Nastran as transient dynamic problem with base enforced motion. It is observed that the...

Suppression of the wing-rock phenomenon using nonlinear controllers

This paper deals with the design of nonlinear controllers for the wing-rock phenomenon of a delta wing aircraft. A fifth order dynamic model is used to describe this phenomenon. A state transformation is introduced such that the transformed dynamic model is in a form which is suitable for a variety of control designs. A feedback linearization control scheme and a sliding-mode control (SMC) scheme are then proposed to suppress wing rock oscillations. It is shown that the two controllers successfully suppress the undesired oscillations and guarantee the asymptotic convergence of all system trajectories to their desired values. The effectiveness of the proposed controllers is verified through simulation studies.

Optimal trends in Manoeuvre Load Control at subsonic and supersonic flight points for tailless delta wing aircraft

Manoeuvre Load Alleviation (MLA) is the concept of redistribution of forces and moments on airframe through optimal actuation of control surfaces. The effect is to minimise the stresses near wing root and improve fatigue life of airframe components, such as, the frequently studied wing root fitting connecting wing to the fuselage. The configuration is a typical tailless delta wing aircraft having inboard and outboard Elevons (a combination of Elevator and Aileron) placed symmetrically on starboard and port side. The problem is formulated as minimisation of independent conflicting multiple objectives of wing root bending and twisting moments, with stability equations as equality constraints and actuator hinge moments as inequality constraints. Hybrid method is used as optimisation technique, which is evolved from the combination of heuristic based Elitist non-dominated Sorting Genetic Algorithm (NSGA-II) and calculus based Goal Programming methods. The primary objective of this paper is to bring out the structural benefits attainable for some of the combined critical manoeuvre load cases at subsonic and supersonic flight points. The combined critical manoeuvre load cases demarcate the limit to which airframe is loaded. The minimisation achieved is better for flight points at supersonic as compared to subsonic Mach numbers.

Wind tunnel testing of a novel wingsuit design

A wingsuit is a special suit that is worn to allow the user to fly after jumping off of a high cliff. The wingsuit creates an airfoil shape by adding wings of material between the arms and the sides as well as a tail consisting of material between the legs. The wingsuit allows for the creation of lift and thus human flying. A new and novel wingsuit design is proposed based on the design of a delta wing aircraft. This new wingsuit has material leading from the side of the head and connecting to the top of the arms, extending the area of the forward wing. Using a mannequin in a wind tunnel, the aerodynamic performance of the new wingsuit will be measured and compared to that of the current wingsuit design. The results show that the redesigned wingsuit had a lower lift-to-drag ratio in most testing scenarios. The decrease in lift-to-drag ratio was due to the combination of an increased lift and a higher increased drag.

State-Space Modeling and Identification ofDelta Wing Vortex-Coupled Roll Dynamics

This paper develops a new state-space model for vortex-coupled 65-degree delta wing aircraft systems based on a modified nonlinear indicial response method combined with an internal state-space representation. Relationships between vortex breakdown location, rolling moment coefficient, and roll angle dynamics are determined. The state-space equations derived are subject to state delays and are also nonlinear in the vortex-coupled rolling moment coefficient Linear and nonlinear parameter identification methods are developed to empirically estimate the rolling moment coefficient as a function of the roll angle and primary vortex breakdown locations. A comparison between numerical simulations and experimental data indicates close agreement for a number of different initial conditions.