Knowledge Base

MATLAB and Simulink for Aerospace Engineering

Aerospace engineering is the science and art of developing aircrafts that not only fly, but do so efficiently. While there are various ways aircrafts can be classified, one of the easiest is to classify them is as commercial, military and spacecrafts. While spacecrafts are mostly developed by government agencies (ISRO in India, NASA in the US, etc.), there are various corporations that develop commercial aero planes and military fighter planes or drones. Irrespective of the type, aero planes are quite versatile atmospheric machines. They all have propellers and wings or machinery to move them through the air, a fuselage, stabilizing and control surfaces such as tails and fins, rudders, landing and takeoff gear, navigational and control systems, electrical and safety gadgets and numerous other components. While the wings produce the aerodynamic lift, the payload (combined weight of passengers, cargo, and baggage), crew, powerplants, and fuel are housed in the fuselage. The two most important aspects of aerospace engineering are airworthiness and price. For commercial aircraft, the specification is primarily the mission profile for the payload range capability, for military aircrafts it can be combat capabilities and speed. In addition, each country adheres to some safety standards. In India, it is the Directorate General of Civil Aviation (DGCA), in the U.S. the Federal Aviation Administration (FAA), and so on. Each aircraft must meet approval of the respective agency from their country before it can fly. Substantiation of airworthiness regulations is mandatory in the aerospace industry, and aerospace engineers need to keep this aspect in mind while developing a new product. There have been numerous incidences where an excellent design was discarded because it did not comply with the regulation authorities.

Math and Science behind Aerospace Engineering
Irrespective of what purpose they serve, all aircrafts follow the same equations of motion in flight. This fact is used to design them and to predict their trajectory and orientation during flight. These tenets are popularly called the six degrees of freedom (6 DOF) equations of motion of a rigid body. As far as aircrafts are concerned, 6 DOF means the ability of aircrafts to move along the 3 axes (X, Y, and Z) and in addition be able to roll, yaw, and pitch. They allow the aerodynamic forces and moments of a body moving through air to be calculated using the aerodynamic coefficient. The physical, analytical, and computational study of the 6 DOF equations of motion for a flight vehicle is what constitutes the subject of flight dynamics. It is the laws governing DOF that distinguishes the flight dynamics of one airplane from another, as well as the nature and magnitude of the aerodynamic forces and moments generated in flight.

Strictly from an engineering perspective (neglecting the commercial aspect), aerospace engineering includes subjects like Mechanics (Both Solid and Fluid), Thermodynamics and Heat transfer, & Materials Science. Computational Fluid Dynamics (CFD) plays a stellar role in aero dynamics. CFD is nothing but harnessing the power of computers to mathematically model a physical phenomenon involving fluid flowand solving it numerically. In case of aero planes, the fluid in question is of course air. Other mathematical topics that aerospace engineering involve include Propulsion, Flight Mechanics, Theory of Mechanics, Aerospace Structures, Manufacturing Processes, and Automatic Control. Needless to say, Linear Algebra (especially matrices and Eigen values and Eigen vectors), Calculus (improper integrals, partial derivatives, differential Calculus, Cauchy and Euler equations, Laplace Transforms), Numerical methods (Taylor's theorem, single and multi-step methods for differential equations) all play an important role in modelling and simulating the flight behaviour.

Modelling and Simulation
The introduction of powerful chips has proved to be a boon for scientists and engineers. Today, using simulation software is an inherent part of aircraft development process. Using 3D modelling and advanced simulation software allows aerospace engineers to evaluate different designs earlier in the development process. Modelling and simulation entails analyzing complex systems, using a combination of theoretical, computational, and experimental techniques. This in turn streamlines the design process by reducing the number of required physical prototypes.

MATLAB and Simulink
It should be clear from above that designing aircrafts that work efficiently involves intense mathematical calculations. Results of the simulation depend upon the mathematical model used, and this is where MATLAB and Simulink assist engineers.

MATLAB from MathWorks is one of the most popular fourth-generation programming languages in the world. It is one of the best numerical analysis environments, geared to assist engineers as well as students. MATLAB is an abbreviation of the term “Matrix Laboratory” since it was initially referred to as the ‘matrix programming language’. MATLAB is one of the most powerful and high-performance language that is used in technical computing. It is built to solve the problems which use mathematics notations. MATLAB is distributed with core functionality, and users can include add-on’s called ‘toolboxes’.  With MATLAB, it is easier to perform numerical linear algebra and perform matrices operations. MATLAB is quite handy for data analysis and visualization as well. It is also possible to develop custom algorithms using MATLAB.

Simulink from MathWorks is an add-on product for MATLAB that creates a graphical, interactive environment for modeling, simulating, and analyzing dynamic systems. Simulink is basically a simulation platform that incorporates MATLAB and a model design system. It features an intuitive and user friendly environment for programming, simulation, modelling and analyzing dynamic systems. Engineers and scientists use Simulink to create mathematical models of physical systems. It is used in a variety of industries, including automotive, aerospace, and communications.

In the aerospace sector, MATLAB is useful in designing autonomous systems, hypersonics, advanced wireless systems, and hybridization and electrification of aircrafts. Simulink allows aerospace engineers to model and simulate a variety of aerospace systems. In the context of system engineering, Simulink also establishes digital thread, providing traceability between requirements, architecture, design, auto-generated code, and testing of artfacts. This ensures design completeness and eases change management of complex systems, all within the same environment. The Aerospace blockset extends the capabilities of Simulink, providing reference examples and blocks for modelling, simulating, and analyzing high-fidelity aircraft and spacecraft platforms. It includes vehicle dynamics, validated models of the flight environment, and blocks for pilot behaviour, actuator dynamics, and propulsion. Together, MATLAB and Simulink provide reliable tools that allow aerospace engineers to develop better prototypes at a faster pace. This is one of the reasons why MATLAB and Simulink are popular in India and abroad.