elements of aerospace engineering and design enme 489l fall 20061 aerodynamic analysis 3 balloons in...
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ENME 489L Fall 2006 1
ELEMENTS OF AEROSPACE ENGINEERING AND DESIGN
Aerodynamic Analysis
3 Balloons in straight line
• Maximum Lift
• Minimum Drag
ENME 489L Fall 2006 2
ELEMENTS OF AEROSPACE ENGINEERING AND DESIGN
Aerodynamic Analysis
Vehicle Mass Estimate:
= mass (thrust system) +mass (steering system)+…….
+etc.
= 0.796 Kg
ENME 489L Fall 2006 3
ELEMENTS OF AEROSPACE ENGINEERING AND DESIGN
Aerodynamic Analysis
Vehicle Drag Estimate:• Assuming Drag is Dominated by balloon
(Frontal Area)
424.02
2
AU
FC dd
ENME 489L Fall 2006 4
ELEMENTS OF AEROSPACE ENGINEERING AND DESIGN
Aerodynamic Analysis
• Assuming Maximum Velocity of 4.4 ft/s:
lbsftFF sft
ft
slugdragthrust 06758.0)4.4)()3(
4)(002329)(.424(.
2
1 223
ENME 489L Fall 2006 5
ELEMENTS OF AEROSPACE ENGINEERING AND DESIGN
Aerodynamic Analysis
System Placement:• All batteries, receivers, & non-thrust
producing equipment placed as close to Center of Gravity as possible, in order to maximize stability
• 4 AA batteries (112g), 1 rechargeable battery pack (105g)
• 2 Motors, placed as far apart as possible, located in the rear of vehicle, in order to maximize steering capabilities
ENME 489L Fall 2006 6
ELEMENTS OF AEROSPACE ENGINEERING AND DESIGN
Aerodynamic Analysis
Method of Vehicle Control:
• One servo to adjust pitch of motors, control elevation (z) of vehicle
• One servo to adjust yaw of motors, control horizontal (x, y) direction of vehicle
ENME 489L Fall 2006 7
ELEMENTS OF AEROSPACE ENGINEERING AND DESIGN
Aerodynamic Analysis
Estimated Duration:
From previous thrust & drag analysis:
statesteadyonacceleratitotal ttt
sec5.70totalt