{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Lecture 1 Introduction

# Lecture 1 Introduction - MAE 4262 ROCKETS AND MISSION...

This preview shows pages 1–8. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: MAE 4262: ROCKETS AND MISSION ANALYSIS Introduction and Course Overview August 17, 2010 Mechanical and Aerospace Engineering Department Florida Institute of Technology D. R. Kirk ROCKET VS. AIR-BREATHING PROPULSION • Capture mass from environment and set that mass in motion backwards → Use reaction force to propel vehicle – Only fuel is carried onboard – Oxidizer (air) is ‘harvested’ continuously during flight – Air-Breathing Engines (MAE: 4261) • Take mass stored in a vehicle and throw it backwards • → Use reaction force to propel vehicle – All fuel and oxidizer are carried onboard the vehicle – Rocket and Mission Analysis (MAE: 4262) WHAT DID NEWTON SAY? ( 29 dt dm V ma F dt dm V dt dV m mV dt d F + = + = = Newton's First and Second laws, in Latin, from the original 1687 edition of the Principia Mathematica. ( 29 ma F dt dm V dt dV m mV dt d F = + = = Mutationem motus proportionalem esse vi motrici impressae, et fieri secundum lineam rectam qua vis illa imprimitur. Baseball Rocket IS THIS CORRECT? HOW ALL(?) ROCKETS WORKS Rocket Propulsion (class of jet propulsion) that produces thrust by ejecting stored matter • Propellants are combined in a combustion chamber where chemically react to form high T&P gases • Gases accelerated and ejected at high velocity through nozzle, imparting momentum to engine • Thrust force of rocket motor is reaction experienced by structure due to ejection of high velocity matter • Same phenomenon which pushes a garden hose backward as water flows from nozzle, gun recoil • Examples to come in next lecture: mass, momentum and derivation of Rocket Equation QUESTION (Hill and Peterson, Chapter 1, p.3): Could a jet or rocket engine exert thrust while discharging into a vacuum (with not atmosphere to “push against”)? ( 29 e e e a e e e V m F A P P V m F =- + = F Chemical Energy Thermal Energy Kinetic Energy HOW AN AIRCRAFT ENGINE WORKS ( 29 ( 29 o e e a e o o e e V V m F A P P V m V m F- ≈- +- = • Flow through engine is conventionally called THRUST – Composed of net change in momentum of inlet and exit air • Fluid that passes around engine is conventionally called DRAG Chemical Energy Thermal Energy Kinetic Energy Force ~ (ingested mass flow) x (exit velocity-inlet velocity) SUMMARY: ESTIMATES FOR THRUST • Points to remember: – Mass flow for rocket is propellant carried onboard (fuel + oxidizer) – Mass for air-breathing engine is fuel carried onboard and air harvested from environment as airplane flies – Rockets usually require far higher thrust levels than airplanes – Airplanes usually fly for far greater durations than rockets ( 29 o e e V V m F V m F- ≈ ≈ Rocket Air-Breathing Engine WHY ROCKET PROPULSION?...
View Full Document

{[ snackBarMessage ]}

### Page1 / 90

Lecture 1 Introduction - MAE 4262 ROCKETS AND MISSION...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online