Aerothermal Propulsion

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Aerothermal Propulsion

• Lecture 1
• Course Overview and Thrust Equation

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Agenda

• Course Overview
• 1 law of Thermodynamics
• Fluid Equations
• Thrust equation

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First jet Aircraft Henri Coanda 1910
Henri Coanda 1885-1972
Discovered the Coanda effect the hard way
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Main Motivation 1944Worlds first operational
jet fighter
Woe unto you when your enemies can fly higher and
faster than you you will soon lose air
superiority
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Motivation Cont.
Loss of air superiority has dramatic consequences
on the ground
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Jet Propulsion
Jet aircraft , unlike propeller aircraft , were
developed primarily for military applications
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Aerothermal Propulsion

• Thermodynamics and Fluid Dynamics of Propulsion
• Thermal Physics of Combustion
• Basic Propulsion Engines (ramjets)
• Jet Turbines and Turbomachinery (low and slow)
• Scramjets (higher and faster)
• Rocket Engines ( where no human has gone before)

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ramjet
Talos long range antiaircraft missile
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Turbine Engines
Low and slow
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Scramjet
Higher and Faster
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Rocket Engines
Higher and Faster Still
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1st law of Thermodynamics
dE dQ PdV Changes in Energy consist of both
heat dQ addition and work PdV on surroundings
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Continuity Equation
 
l     
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Continuity Equation Cont.
which becomes as ? x ? 0.
 
l      Similar analysis can be done for the
fluxes across the other four faces to yield the
continuity equation, which can also be written
as .
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Divergence
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Force per unit volume without viscosity
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Energy Equation without viscosity
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Energy Equation cont.
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Enthalpy
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Enthalpy Cont.
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Enthalpy Importance
Energy release in an unconfined space
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Thrust From Force Equation
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Thrust From Force Equation
Air breathing engine
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Thrust From Force Equation
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Thrust Equation
Change in flow momentum
Change in pressure (Normally Pe Pa)