Module overview
This module further develops the fundamental concepts underpinning aircraft flight, stability, and control. The focus is initially on capturing the aerodynamic behaviour of lifting and control surfaces within simple mathematical models leading to simple 3-DOF equations of motion for a rigid aircraft.
Ideas of equilibrium and trim are captured by determining the steady control inputs needed to fly simple steady trajectories, including feasibility, conditional static stability, and drag optimality. These concepts are extended into three-dimensions using ideas of motion as a geometric transformation leading to the full 6-DOF dynamical systems, state space formulation, and flight simulators; linearization about a steady trajectory leads to linear state space models, characteristic motions and dynamic stability, response to gusts, stability augmentation, and linear control. The lectures are complemented by problem classes.
Linked modules
Pre-requisites: SESA1015 and SESA2022
Aims and Objectives
Learning Outcomes
Subject Specific Practical Skills
Having successfully completed this module you will be able to:
- Demonstrate study and time management skills. [G2(m)]
- Solve problems. [SM3(m),EA1(m),EA3(m),G1(m)]
- Study and learn both independently. [P4(m),G2(m)]
- Appreciate some of the technical issues associated with aerospace vehicle design. [D1(m),D2(m)]
Knowledge and Understanding
Having successfully completed this module, you will be able to demonstrate knowledge and understanding of:
- Control inputs for steady sideslip, coordinated turns. Linear response to control inputs and wind gusts. Simple state feedback and autopilots. [SM1(m),SM3(m),SM4(m),SM6(m),EA1(m),EA3(m),EA6(m),P1(m),P6(m)]
- Linearised state space equations for small disturbances about a steady trajectory, aerodynamic derivatives, longitudinal and lateral characteristic motions, eigenmodes, dynamic stability. [SM1(m),SM6(m),EA1(m),EA3(m),P1(m)]
- Description of motion in three-dimensions, Euler angles and rates, full 6-DOF equations for rigid symmetrical aircraft, state space formulation, solution in the time domain and flight simulation. [SM1(m),EA1(m),P1(m)]
- Aerodynamic and control forces acting on aircraft, including high-lift devices, origins of drag. [SM1(m),EA1(m),P1(m)]
- Aircraft equilibrium, control/trim inputs required for steady trajectories, static stability, optimality. [SM1(m),EA1(m),P1(m)]
Subject Specific Intellectual and Research Skills
Having successfully completed this module you will be able to:
- Perform simple calculations and computations of aircraft characteristic motions in both timedomain and in terms of eigenmodes [EA2(m),G1(m),P6(m)]
- Analyse aircraft lift/drag/moment data. [EA6(m),P6(m)]
- Perform simple calculations of aircraft trim, lift and drag, static stability. [SM3(m)]
Transferable and Generic Skills
Having successfully completed this module you will be able to:
- Solve problems systematically. [SM3(m),EA1(m),EA3(m),G1(m)]
- Study and learn independently. [P4(m),G2(m)]
- Demonstrate study and time management skills. [G2(m)]
Syllabus
Part A
Aerodynamic forces and moments:
Nomenclature, aircraft axes, lifting and control surfaces, high-lift devices, aerodynamic derivatives, aerodynamic centre, induced flow and downwash, aerodynamic derivatives and neutral point for complete aircraft.
Aircraft performance:
Thrust, drag, stall, compressibility effects, wing sweep, trim tabs. Effects of high-lift devices, optimal trim configurations and minimum drag.
Aircraft equilibrium and static stability:
Control and trim inputs for steady equilibrium level flight, steady climb, manoeuvring with constant acceleration. Stick-fixed and stick-free static stability, static margins, lateral static stability.
Part B
Aircraft motion in three-dimensions:
Motion as geometric transformation, aircraft body and Earth axes, rotation matrices, Euler angles, Euler rates and angular velocity, transformation of vector quantities, inertial time derivative, gravitation effects. Estimation of orientation from inertial sensors, autopilots. Full 6-DOF equations for a rigid aircraft, state space formulation. Solution in the time domain, flight simulators.
Small disturbance equations:
Linearization about steady equilibrium flight, wind axes, stability and control derivatives, matrix representation, eigenvalues and eigenvectors of characteristic motions, dynamic stability, linear state space formulations, decoupling of longitudinal and lateral motions for symmetric aircraft.
Longitudinal dynamic stability:
Wind axes and aerodynamic derivatives, gravitational effects. Stick-fixed dynamic stability, Routh–Hurwitz criterion, eigenvalues and eigenvectors of characteristic motions. Phugoid and short period
oscillations. Reduced order models and longitudinal approximations. Handling qualities.
Lateral dynamic stability:
Eigenvalues and eigenvectors of characteristic motions. Dutch roll, spiral mode and roll subsidence. Reduced order models. Handling qualities. State space formulation for response and control
applications. Estimation of lateral aerodynamic derivatives. Reduced order models and lateral approximations. Steady sideslip and correctly-banked turn.
Control and Response:
Control inputs to achieve a given trajectory, stability augmentation and state feedback, autopilots and flight control. Response to wind gusts.
Revision and Problem Class lectures.
Learning and Teaching
Teaching and learning methods
Teaching methods : lectures supplemented by problem classes.
Learning activities include directed reading and online quizzes.
Type | Hours |
---|---|
Teaching | 33 |
Independent Study | 101 |
Completion of assessment task | 16 |
Total study time | 150 |
Assessment
Summative
This is how we’ll formally assess what you have learned in this module.
Method | Percentage contribution |
---|---|
Continuous Assessment | 20% |
Final Assessment | 80% |
Referral
This is how we’ll assess you if you don’t meet the criteria to pass this module.
Method | Percentage contribution |
---|---|
Set Task | 100% |
Repeat
An internal repeat is where you take all of your modules again, including any you passed. An external repeat is where you only re-take the modules you failed.
Method | Percentage contribution |
---|---|
Set Task | 100% |
Repeat Information
Repeat type: Internal & External