Currently viewing the category: "Aerodynamics"

Jet Engine Design: The Turbine

On April 6, 2013 · In Aerodynamics, Manufacturing, Technology

The turbine is at the heart of any jet engine with its primary task being to drive the compressor. As described previously  without the compressor no mechanical work would be done on the fluid prior combustion and the thrust produced would only be a function of the chemical energy […]

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Jet Engine Detail Design: The Compressor

On January 11, 2013 · In Aerodynamics

In this post the design of jet engine compressors will be discussed leading to the definition of ballpark performance parameters. For smaller engines centrifugal (CF) compressors are used since they can handle smaller flow rates more effectively and are more compact than axial compressors. Axial compressors however have the advantage of a smaller frontal area […]

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Jet Engine Design and Optimisation

On January 4, 2013 · In Aerodynamics, Case Studies

For aircraft jet propulsion there are in general four distinct designs: the turbojet, turbofan (or bypass engine), turboprop and turboshaft. This post will address the layout and design of the two most common engines used in modern aircraft, the turbojet and turbofan, and explain how their characteristics make each engine applicable for a specific task. […]

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Thrust Reversal

On August 22, 2012 · In Aerodynamics, Technology

In a typical turbofan jet engine the oncoming airflow is compressed throughout a series of compressor stages, mixed with a fuel (typically kerosene) and combusted, drastically increasing pressure and temperature, and then expanded through a nozzle to provide thrust towards the rear of the aircraft. By accelerating the fluid towards aft, Newton’s Third Law implies […]

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The Scramjet

On August 17, 2012 · In Aerodynamics, News, Technology

The American Air Force has reported that a test of the unmanned hypersonic X-51A “Waverider” scramjet has failed. During the test flight the aircraft disconnected successfully from the the wing of a B-52 bomber but only 16 seconds later a defect in a control fin caused the “Waverider” to spiral out of control and eventually […]

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Reducing Skin-Friction Drag by Laminar Flow

On April 28, 2012 · In Aerodynamics, History

In a previous post I introduced the concept of skin-friction and pressure drag, and discussed the contradicting aerodynamic conditions to minimise either of the two types of drag. Overall the minimum resistance of slender shapes (such as aerofoils) to a fluid is attained with an attached laminar […]

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High-Lift Devices

On April 21, 2012 · In Aerodynamics, Bio-mimicry

In a previous post I introduced the concept of boundary layer separation and how aquatic animals actively or passively morph their skins to delay this phenomenon. As a brief recap, when flow over a surface encounters an adverse pressure gradient (i.e. the fluid pressure increases in […]

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Bio-mimetic Drag Reduction – Part 3: Morphing

On April 5, 2012 · In Aerodynamics, Bio-mimicry

In the previous two posts of this blog series I introduced the different sensing mechanism that aquatic animals possess to create spatial images of the largely turbulent flow fields around them. Flow sensing has been shown to […]

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Bio-mimetic Drag Reduction – Part 2: Aero- and Hydrodynamics

On March 31, 2012 · In Aerodynamics, Bio-mimicry

Part 1 of this blog series outlined the different sensing mechanisms that aquatic animals possess to create spatial images of the flow fields around them. In summary fish were found to possess a network of mechanosensors distributed over their bodies called the lateral line. The lateral line […]

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