16.540 Spring 2006
PRESSURE FIELDS AND UPSTREAM INFLUENCE
1
PLAN OF THE LECTURE
Pressure fields and streamline curvature
Streamwise and normal pressure gradients
Onedimensional versus multidimensional flows
Upstream influence and component coupling
H
16.512, Rocket Propulsion
Prof. Manuel MartinezSanchez
Lecture 22: Liquid Motors: Combustion Instability (Low Frequency)
Combustion Stability
1. General Discussion
Elimination of instabilities has been historically one of the largest components
of all ne
Team Modeling Project for 16.540
Due Date: 4 May 2006 Credit: 20% of course grade Project Objective: Formulate and implement a model of an internal flow phenomenon which makes a clear statement about some aspect of the flow which you: i) find interesting
16.540  Internal Flows
Spring 2006
Practice Concept Quiz #2
1. [Used as Concept Quiz #3 (2004)] We have seen that whether a flow is rotational or not can
have a major difference on its behavior. Below are some examples of situations encountered in
fluids
16.540  Internal Flows
Spring 2006
Practice Concept Quiz Questions
1. A perfect gas is passed through a sudden expansion in a duct. The expansion area ratio is
three. Just downstream of the expansion an amount of heat, Q, per unit time, is added to the
s
SOME COMMENTS ON MODELING FLUID FLOW
16.540 Notes
Spring 2006
E. Greitzer, C. Tan
1
MESSAGES
In problems of technological interest, there are often many levels of
approach possible
There are also many levels of data that can be examined
Not all the data i
16.540 CLASS FORMAT AND STRUCTURE
16.540 Notes
Spring 2006
E. Greitzer, C. Tan
1
MESSAGE
Active learning (active engagement of students with the material
during class) is helpful and useful in the learning process
The conduct of the class is built around
16.522, Space Propulsion
Prof. Manuel MartinezSanchez
Lecture 2325: COLLOIDAL ENGINES
APPENDIX
A1. INTRODUCTION. Colloidal thrusters are electrostatic accelerators of charged
liquid droplets. They were first proposed and then intensively studied from ar
16.522, Space Propulsion
Prof. Manuel MartinezSanchez
Lecture 22: A Simple Model For MPD Performanceonset
It is well known that rapidly pulsed current tends to concentrate near the surface of
copper conductors forming a skin. A similar effect occurs whe
16.522, Space Propulsion
Prof. Manuel MartinezSanchez
Lecture 21: Electrostatic versus Electromagnetic Thrusters
Ion Engine and Colloid Thrusters are Electrostatic devices, because the electrostatic
forces that accelerate the ions (or droplets) are also
16.522, Space Propulsion Prof. Manuel MartinezSanchez Lecture 18: Hall Thruster Efficiency For a given mass flow m and thrust F, we would like to minimize the running power P. Define a thruster efficiency
2 F i = 2 m P
2 where F i is the minimum required
16.522, Space Propulsion
Prof. Manuel MartinezSanchez
Lecture 17: NOTES ON HALL THRUSTERS
NOTES ON HALL THRUSTERS
1. Introduction
Hall thrusters are electrostatic ion accelerators in which the grid system (which
serves in classical ion engines to anchor
16.522, Space Propulsion
Prof. Manuel MartinezSanchez
Lecture 16: Ion Engine Performance. Brophys Theory
DEFINITIONS:
JB=Beam ion (and neutralizer
electron current)
JE=cathode emitted current
Jc=ion current to cathodepotential surfaces
JD=current through
16.522, Space Propulsion Prof. Manuel MartinezSanchez Lecture 15: Thrust Calculation (Single Grid, Single Potential)
d 1 2 Ex dx 2
d d E2 Fx dEx = chEx dx = 0 Ex dx = 0 x A dx 2 0 0 d
0
x = Va d Ex =0
43
Ex =
Va 4 x d 3 d
13
0
Ex
d
=
4 Va 3 d
2 Fx 16
16.522, Space Propulsion Prof. Manuel MartinezSanchez Lecture 1314: Electrostatic Thrusters Outline 1 Introduction 2 Principles of Operation. 3 Ion Extraction and Acceleration. 4 Ion Production. 4.1 Physical Processes in Electron Bombardment Ionization
16.522, Space Propulsion
Prof. Manuel MartinezSanchez
Lecture 1112: SIMPLIFIED ANALYSIS OF ARCJET OPERATION
1. Introduction
These notes aim at providing orderofmagnitude results and at illuminating the
mechanisms involved. Numerical precision will be
16.522, Space Propulsion
Prof. Manuel MartinezSanchez
Lecture 9: Some Examples of Small Solid
Propellant Rockets for Inspace Propulsion
The STAR 13B incorporates the lightweight case developed for the STAR 13 with the
propellant and nozzle design of the
16.522, Space Propulsion
Prof. Manuel MartinezSanchez
Lecture 7: Bipropellant Chemical Thrusters and Chemical Propulsion
Systems Considerations (Valving, tanks, etc)
Characteristics of some monopropellants (Reprinted from H. Koelle, Handbook
of Astronaut
16.522, Space Propulsion
Prof. Manuel MartinezSanchez
Lecture 6: Hydrazine Decomposition: Performance Estimates
(3)
Electrothermal Augmentation Concept
Geostationary satellites are most of the time exposed to the sun, but they still are
subject to eclips
16.522, Space Propulsion
Prof. Manuel MartinezSanchez
Lecture 5: Chemical Thrusters for InSpace Propulsion
HYDRAZINE
Hydrazine was first isolated by Curtius in 1887, and in 1907 a suitable synthetic
method was developed by Raschig. Anhydrous hydrazine i
16.522, Space Propulsion
Prof. Manuel MartinezSanchez
Lecture 4: Repositioning in Orbits
Suppose we want to move a satellite in a circular orbit to a position apart in the
same orbit, in a time t (assumed to be several orbital times at least). The gener
16.522, Space Propulsion
Prof. Manuel MartinezSanchez
Lecture 3: Approximate V for LowThrust Spiral Climb
Assume initial circular orbit, at v = vco =
.
r0
Thrust is applied tangentially.
F
Call a= .
M
By conservation of energy, assuming the orbit remain
16.522, Space Propulsion
Prof. Manuel MartinezSanchez
Lecture 2: Mission Analysis for Low Thrust
1. Constant Power and Thrust: Prescribed Mission Time
Starting with a mass M0 , and operating for a time t an electric thruster of jet speed
c, such as to ac
16.522, Space Propulsion
Prof. Manuel MartinezSanchez
Lecture 1b: Review of Rocket Propulsion
The only practical way to accelerate something in free space is by reaction. The idea
is the same as in air breathing propulsion (to push something backwards) b
16.512, Rocket Propulsion
Prof. Manuel MartinezSanchez
Lecture 37: Future Developments
Some (dangerous) Forecasts on the Future of High Thrust Rockets (Chemical or
Nuclear)
Looking ahead in Rocketry
Liquid Rockets :

No increase in Isp to be expected.

16.512, Rocket Propulsion
Prof. Manuel MartinezSanchez
Lecture 3536: Impulsive and LowThrust Maneuvers in Space
See Lectures 34 of 16.522 (Space Propulsion) for coverage of Low Thrust
Maneuvers and Repositing within an orbit.
We add here material on
16.512, Rocket Propulsion Prof. Manuel MartinezSanchez Lecture 34: Performance to GEO
V Calculations for Launch to Geostationary Orbit (GEO)
Idealized Direct GTO Injection (GTO = Geosynchronous Transfer Orbit) Assumptions: Ignore drag and "gravity" losse
16.512, Rocket Propulsion
Prof. Manuel MartinezSanchez
Lecture 33: Performance to LEO
V Calculations for Launches to Low Earth Orbit (LEO)
Ideal Earthtoorbit launch
'
V1 cos RE = v2 R
V12
V '2
=2
RE
R
2
2
2
=
RE
1
V1 cos
2
R
R
V12 = 2
V1 =
vc =
R
R
16.512, Rocket Propulsion
Prof. Manuel MartinezSanchez
Lecture 32: Orbital Mechanics: Review, Staging
Mission Planning, Staging
The remaining lectures are devoted to Mission Planning and Vehicle Design, which in
reality occurs even before the rocket engi