A Study of Variable Thrust, Variable Specific Impulse Trajectories For
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Astrodynamics
Politecnico di Torino SEEDS SpacE Exploration and Development Systems Astrodynamics II Edition 2006 - 07 - Ver. 2.0.1 Author: Guido Colasurdo Dipartimento di Energetica Teacher: Giulio Avanzini Dipartimento di Ingegneria Aeronautica e Spaziale e-mail: [email protected] Contents 1 Two–Body Orbital Mechanics 1 1.1 BirthofAstrodynamics: Kepler’sLaws. ......... 1 1.2 Newton’sLawsofMotion ............................ ... 2 1.3 Newton’s Law of Universal Gravitation . ......... 3 1.4 The n–BodyProblem ................................. 4 1.5 Equation of Motion in the Two-Body Problem . ....... 5 1.6 PotentialEnergy ................................. ... 6 1.7 ConstantsoftheMotion . .. .. .. .. .. .. .. .. .... 7 1.8 TrajectoryEquation .............................. .... 8 1.9 ConicSections ................................... 8 1.10 Relating Energy and Semi-major Axis . ........ 9 2 Two-Dimensional Analysis of Motion 11 2.1 ReferenceFrames................................. 11 2.2 Velocity and acceleration components . ......... 12 2.3 First-Order Scalar Equations of Motion . ......... 12 2.4 PerifocalReferenceFrame . ...... 13 2.5 FlightPathAngle ................................. 14 2.6 EllipticalOrbits................................ ..... 15 2.6.1 Geometry of an Elliptical Orbit . ..... 15 2.6.2 Period of an Elliptical Orbit . ..... 16 2.7 Time–of–Flight on the Elliptical Orbit . .......... 16 2.8 Extensiontohyperbolaandparabola. ........ 18 2.9 Circular and Escape Velocity, Hyperbolic Excess Speed . .............. 18 2.10 CosmicVelocities -
Aerospace Engine Data
AEROSPACE ENGINE DATA Data for some concrete aerospace engines and their craft ................................................................................. 1 Data on rocket-engine types and comparison with large turbofans ................................................................... 1 Data on some large airliner engines ................................................................................................................... 2 Data on other aircraft engines and manufacturers .......................................................................................... 3 In this Appendix common to Aircraft propulsion and Space propulsion, data for thrust, weight, and specific fuel consumption, are presented for some different types of engines (Table 1), with some values of specific impulse and exit speed (Table 2), a plot of Mach number and specific impulse characteristic of different engine types (Fig. 1), and detailed characteristics of some modern turbofan engines, used in large airplanes (Table 3). DATA FOR SOME CONCRETE AEROSPACE ENGINES AND THEIR CRAFT Table 1. Thrust to weight ratio (F/W), for engines and their crafts, at take-off*, specific fuel consumption (TSFC), and initial and final mass of craft (intermediate values appear in [kN] when forces, and in tonnes [t] when masses). Engine Engine TSFC Whole craft Whole craft Whole craft mass, type thrust/weight (g/s)/kN type thrust/weight mini/mfin Trent 900 350/63=5.5 15.5 A380 4×350/5600=0.25 560/330=1.8 cruise 90/63=1.4 cruise 4×90/5000=0.1 CFM56-5A 110/23=4.8 16 -
The Velocity Dispersion Profile of the Remote Dwarf Spheroidal Galaxy
The Velocity Dispersion Profile of the Remote Dwarf Spheroidal Galaxy Leo I: A Tidal Hit and Run? Mario Mateo1, Edward W. Olszewski2, and Matthew G. Walker3 ABSTRACT We present new kinematic results for a sample of 387 stars located in and around the Milky Way satellite dwarf spheroidal galaxy Leo I. These spectra were obtained with the Hectochelle multi-object echelle spectrograph on the MMT, and cover the MgI/Mgb lines at about 5200A.˚ Based on 297 repeat measure- ments of 108 stars, we estimate the mean velocity error (1σ) of our sample to be 2.4 km/s, with a systematic error of 1 km/s. Combined with earlier re- ≤ sults, we identify a final sample of 328 Leo I red giant members, from which we measure a mean heliocentric radial velocity of 282.9 0.5 km/s, and a mean ± radial velocity dispersion of 9.2 0.4 km/s for Leo I. The dispersion profile of ± Leo I is essentially flat from the center of the galaxy to beyond its classical ‘tidal’ radius, a result that is unaffected by contamination from field stars or binaries within our kinematic sample. We have fit the profile to a variety of equilibrium dynamical models and can strongly rule out models where mass follows light. Two-component Sersic+NFW models with tangentially anisotropic velocity dis- tributions fit the dispersion profile well, with isotropic models ruled out at a 95% confidence level. Within the projected radius sampled by our data ( 1040 pc), ∼ the mass and V-band mass-to-light ratio of Leo I estimated from equilibrium 7 models are in the ranges 5-7 10 M⊙ and 9-14 (solar units), respectively. -
Go, No-Go for Apollo Based on Orbital Life Time
https://ntrs.nasa.gov/search.jsp?R=19660014325 2020-03-24T02:45:56+00:00Z I L GO, NO-GO FOR APOLLO BASED ON ORBITAL LIFE TIME I hi 01 GPO PRICE $ Q N66(ACCESSION -2361 NUMBER1 4 ITHRU) Pf - CFSTI PRICE(S) $ > /7 (CODE) IPAGES) 'I 2 < -55494 (CATEGORY) f' (NASA CR OR rwx OR AD NUMBER) Hard copy (HC) /# d-a I Microfiche (M F) I By ff653 Julv65 F. 0. VONBUN NOVEMBER 1965 t GODDARD SPACE FLIGHT CENTER GREENBELT, MARYLAND ABSTRACT A simple expression for the go, no-go criterion is derived in analytical form. This provides a better understanding of the prob- lems involved which is lacking when large computer programs are used. A comparison between "slide rule" results and computer re- sults is indicated on Figure 2. An example is given using a 185 km near circular parking or- bit. It is shown that a 3a speed error of 6 m/s and a 3c~flight path angle error of 4.5 mrad result in a 3c~perigee error of 30 km which is tolerable when a 5 day orbital life time of the Apollo (SIVB + Service + Command Module) is required. iii CONTENTS Page INTRODUCTION ...................................... 1 I. VARLATIONAL EQUATION FOR THE PERIGEE HEIGHT h,. 1 11. THE ERROR IN THE ORBITAL PERIGEE HEIGHT ah,. 5 III. CRITERION FOR GO, NO-GO IN SIMPLE FORM . 5 REFERENCES ....................................... 10 LIST OF ILLUSTRATIONS Figure Page 1 Orbital Insertion Geometry . 2 2 Perigee Error for Apollo Parking Orbits (e 0, h, = 185 km) . 6 3 Height of the Apollo Parking Orbit After Insertion . -
6. Chemical-Nuclear Propulsion MAE 342 2016
2/12/20 Chemical/Nuclear Propulsion Space System Design, MAE 342, Princeton University Robert Stengel • Thermal rockets • Performance parameters • Propellants and propellant storage Copyright 2016 by Robert Stengel. All rights reserved. For educational use only. http://www.princeton.edu/~stengel/MAE342.html 1 1 Chemical (Thermal) Rockets • Liquid/Gas Propellant –Monopropellant • Cold gas • Catalytic decomposition –Bipropellant • Separate oxidizer and fuel • Hypergolic (spontaneous) • Solid Propellant ignition –Mixed oxidizer and fuel • External ignition –External ignition • Storage –Burn to completion – Ambient temperature and pressure • Hybrid Propellant – Cryogenic –Liquid oxidizer, solid fuel – Pressurized tank –Throttlable –Throttlable –Start/stop cycling –Start/stop cycling 2 2 1 2/12/20 Cold Gas Thruster (used with inert gas) Moog Divert/Attitude Thruster and Valve 3 3 Monopropellant Hydrazine Thruster Aerojet Rocketdyne • Catalytic decomposition produces thrust • Reliable • Low performance • Toxic 4 4 2 2/12/20 Bi-Propellant Rocket Motor Thrust / Motor Weight ~ 70:1 5 5 Hypergolic, Storable Liquid- Propellant Thruster Titan 2 • Spontaneous combustion • Reliable • Corrosive, toxic 6 6 3 2/12/20 Pressure-Fed and Turbopump Engine Cycles Pressure-Fed Gas-Generator Rocket Rocket Cycle Cycle, with Nozzle Cooling 7 7 Staged Combustion Engine Cycles Staged Combustion Full-Flow Staged Rocket Cycle Combustion Rocket Cycle 8 8 4 2/12/20 German V-2 Rocket Motor, Fuel Injectors, and Turbopump 9 9 Combustion Chamber Injectors 10 10 5 2/12/20 -
Enhancement of Volumetric Specific Impulse in HTPB/Ammonium Nitrate Mixed
Utah State University DigitalCommons@USU All Graduate Plan B and other Reports Graduate Studies 12-2016 Enhancement of Volumetric Specific Impulse in TPB/H Ammonium Nitrate Mixed Hybrid Rocket Systems Jacob Ward Forsyth Utah State University Follow this and additional works at: https://digitalcommons.usu.edu/gradreports Part of the Propulsion and Power Commons Recommended Citation Forsyth, Jacob Ward, "Enhancement of Volumetric Specific Impulse in TPB/AmmoniumH Nitrate Mixed Hybrid Rocket Systems" (2016). All Graduate Plan B and other Reports. 876. https://digitalcommons.usu.edu/gradreports/876 This Report is brought to you for free and open access by the Graduate Studies at DigitalCommons@USU. It has been accepted for inclusion in All Graduate Plan B and other Reports by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. ENHANCEMENT OF VOLUMETRIC SPECIFIC IMPULSE IN HTPB/AMMONIUM NITRATE MIXED HYBRID ROCKET SYSTEMS by Jacob W. Forsyth A report submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in Aerospace Engineering Approved: ______________________ ____________________ Stephen A. Whitmore Ph.D. David Geller Ph.D. Major Professor Committee Member ______________________ Rees Fullmer Ph.D. Committee Member UTAH STATE UNIVERSITY Logan, Utah 2016 ii Copyright © Jacob W. Forsyth 2016 All Rights Reserved iii ABSTRACT Enhancement of Volumetric Specific Impulse in HTPB/Ammonium Nitrate Mixed Hybrid Rocket Systems by Jacob W. Forsyth, Master of Science Utah State University, 2016 Major Professor: Dr. Stephen A. Whitmore Department: Mechanical and Aerospace Engineering Hybrid rocket systems are safer and have higher specific impulse than solid rockets. However, due to large oxidizer tanks and low regression rates, hybrid rockets have low volumetric efficiency and very long longitudinal profiles, which limit many of the applications for which hybrids can be used. -
PHY140Y 3 Properties of Gravitational Orbits
PHY140Y 3 Properties of Gravitational Orbits 3.1 Overview • Orbits and Total Energy • Elliptical, Parabolic and Hyperbolic Orbits 3.2 Characterizing Orbits With Energy Two point particles attracting each other via gravity will cause them to move, as dictated by Newton’s laws of motion. If they start from rest, this motion will simply be along the line separating the two points. It is a one-dimensional problem, and easily solved. The two objects collide. If the two objects are given some relative motion to start with, then it is easy to convince yourself that a collision is no longer possible (so long as these particles are point-like). In our discussion of orbits, we will only consider the special case where one object of mass M is much heavier than the smaller object of mass m. In this case, although the larger object is accelerated toward the smaller one, we will ignore that acceleration and assume that the heavier object is fixed in space. There are three general categories of motion, when there is some relative motion, which we can characterize by the total energy of the object, i.e., E ≡ K + U (1) 1 GMm = mv2 − , (2) 2 r2 where K and U are the kinetic and gravitational energy, respectively. 3.3 Energy < 0 In this case, since the total energy is negative, it is not possible for the object to get too far from the mass M, since E = K + U<0 (3) 1 GMm ⇒ mv2 = + E (4) 2 r GM ⇒ r = (5) 1 2 − E 2 v m GM ⇒ r< , (6) −E since r will take on its maximum value when the denominator is minimized (or when v is the smallest value possible, ie. -
Spacex Rocket Data Satisfies Elementary Hohmann Transfer Formula E-Mail: [email protected] and [email protected]
IOP Physics Education Phys. Educ. 55 P A P ER Phys. Educ. 55 (2020) 025011 (9pp) iopscience.org/ped 2020 SpaceX rocket data satisfies © 2020 IOP Publishing Ltd elementary Hohmann transfer PHEDA7 formula 025011 Michael J Ruiz and James Perkins M J Ruiz and J Perkins Department of Physics and Astronomy, University of North Carolina at Asheville, Asheville, NC 28804, United States of America SpaceX rocket data satisfies elementary Hohmann transfer formula E-mail: [email protected] and [email protected] Printed in the UK Abstract The private company SpaceX regularly launches satellites into geostationary PED orbits. SpaceX posts videos of these flights with telemetry data displaying the time from launch, altitude, and rocket speed in real time. In this paper 10.1088/1361-6552/ab5f4c this telemetry information is used to determine the velocity boost of the rocket as it leaves its circular parking orbit around the Earth to enter a Hohmann transfer orbit, an elliptical orbit on which the spacecraft reaches 1361-6552 a high altitude. A simple derivation is given for the Hohmann transfer velocity boost that introductory students can derive on their own with a little teacher guidance. They can then use the SpaceX telemetry data to verify the Published theoretical results, finding the discrepancy between observation and theory to be 3% or less. The students will love the rocket videos as the launches and 3 transfer burns are very exciting to watch. 2 Introduction Complex 39A at the NASA Kennedy Space Center in Cape Canaveral, Florida. This launch SpaceX is a company that ‘designs, manufactures and launches advanced rockets and spacecraft. -
An Investigation of the Performance Potential of A
AN INVESTIGATION OF THE PERFORMANCE POTENTIAL OF A LIQUID OXYGEN EXPANDER CYCLE ROCKET ENGINE by DYLAN THOMAS STAPP RICHARD D. BRANAM, COMMITTEE CHAIR SEMIH M. OLCMEN AJAY K. AGRAWAL A THESIS Submitted in partial fulfillment of the requirements for the degree of Master of Science in the Department of Aerospace Engineering and Mechanics in the Graduate School of The University of Alabama TUSCALOOSA, ALABAMA 2016 Copyright Dylan Thomas Stapp 2016 ALL RIGHTS RESERVED ABSTRACT This research effort sought to examine the performance potential of a dual-expander cycle liquid oxygen-hydrogen engine with a conventional bell nozzle geometry. The analysis was performed using the NASA Numerical Propulsion System Simulation (NPSS) software to develop a full steady-state model of the engine concept. Validation for the theoretical engine model was completed using the same methodology to build a steady-state model of an RL10A-3- 3A single expander cycle rocket engine with corroborating data from a similar modeling project performed at the NASA Glenn Research Center. Previous research performed at NASA and the Air Force Institute of Technology (AFIT) has identified the potential of dual-expander cycle technology to specifically improve the efficiency and capability of upper-stage liquid rocket engines. Dual-expander cycles also eliminate critical failure modes and design limitations present for single-expander cycle engines. This research seeks to identify potential LOX Expander Cycle (LEC) engine designs that exceed the performance of the current state of the art RL10B-2 engine flown on Centaur upper-stages. Results of this research found that the LEC engine concept achieved a 21.2% increase in engine thrust with a decrease in engine length and diameter of 52.0% and 15.8% respectively compared to the RL10B-2 engine. -
Propulsione Aeronautica 2020/2021 Francesco Barato
PROPULSIONE AERONAUTICA 2020/2021 FRANCESCO BARATO MATERIALE DI SUPPORTO FONDAMENTI DI PROPULSIONE AERONAUTICA Thrust 푇 = (푚̇ 푎 + 푚̇ 푓)푉푒 − 푚̇ 푎푉0 + (푝푒 − 푝푎)퐴푒 푇 ≈ 푚̇ 푎(푉푒 − 푉0) + (푝푒 − 푝푎)퐴푒 1 PROPULSIONE AERONAUTICA 2020/2021 FRANCESCO BARATO Ramjet P-270 Moskit (left), BrahMos (right) Turboramjet Pratt & Whitney J-58 turbo(ram)jet 2 PROPULSIONE AERONAUTICA 2020/2021 FRANCESCO BARATO Scramjet 3 PROPULSIONE AERONAUTICA 2020/2021 FRANCESCO BARATO Specific impulse 푇 푉푒 푇 푚̇ 푝 푉푒 − 푉0 퐼푠푝 = = [푠] 푟표푐푘푒푡푠 퐼푠푝 = = [푠] 푎푟 푏푟푒푎푡ℎ푛푔 푚̇ 푝푔0 푔0 푚̇ 푓푔0 푚̇ 푓 푔0 4 PROPULSIONE AERONAUTICA 2020/2021 FRANCESCO BARATO Propulsive efficiency Overall efficiency Overall efficiency with Mach number 5 PROPULSIONE AERONAUTICA 2020/2021 FRANCESCO BARATO Engine bypass ratios Bypass Engine Name Major applications ratio turbojet early jet aircraft, Concorde 0.0 SNECMA M88 Rafale 0.30 GE F404 F/A-18, T-50, F-117 0.34 PW F100 F-16, F-15 0.36 Eurojet EJ200 Typhoon 0.4 Klimov RD-33 MiG-29, Il-102 0.49 Saturn AL-31 Su-27, Su-30, J-10 0.59 Kuznetsov NK-144A Tu-144 0.6 PW JT8D DC-9, MD-80, 727, 737 Original 0.96 Soloviev D-20P Tu-124 1.0 Kuznetsov NK-321 Tu-160 1.4 GE Honda HF120 HondaJet 2.9 RR Tay Gulfstream IV, F70, F100 3.1 GE CF6-50 A300, DC-10-30,Lockheed C-5M Super Galaxy 4.26 PowerJet SaM146 SSJ 100 4.43 RR RB211-22B TriStar 4.8 PW PW4000-94 A300, A310, Boeing 767, Boeing 747-400 4.85 Progress D-436 Yak-42, Be-200, An-148 4.91 GE CF6-80C2 A300-600, Boeing 747-400, MD-11, A310 4.97-5.31 RR Trent 700 A330 5.0 PW JT9D Boeing 747, Boeing 767, A310, DC-10 5.0 6 PROPULSIONE -
Interplanetary Trajectory Design Using Dynamical Systems Theory THESIS REPORT by Linda Van Der Ham
Interplanetary Trajectory Design using Dynamical Systems Theory THESIS REPORT by Linda van der Ham 8 February 2012 The image on the front is an artist impression of the Interplanetary Super- highway [NASA, 2002]. Preface This MSc. thesis forms the last part of the curriculum of Aerospace Engineering at Delft University of Technology in the Netherlands. It covers subjects from the MSc. track Space Exploration, focusing on astrodynamics and space missions, as well as new theory as studied in the literature study performed previously. Dynamical Systems Theory was one of those new subjects, I had never heard of before. The existence of a so-called Interplanetary Transport Network intrigued me and its use for space exploration would mean a total new way of transfer. During the literature study I did not find any practical application of the the- ory to interplanetary flight, while it was stated as a possibility. This made me wonder whether it was even an option, a question that could not be answered until the end of my thesis work. I would like to thank my supervisor Ron Noomen, for his help and enthusi- asm during this period; prof. Wakker for his inspirational lectures about the wonders of astrodynamics; the Tudat group, making research easier for a lot of students in the future. My parents for their unlimited support in every way. And Wouter, for being there. Thank you all and enjoy! i ii Abstract In this thesis, manifolds in the coupled planar circular restricted three-body problem (CR3BP) as means of interplanetary transfer are examined. The equa- tions of motion or differential equations of the CR3BP are studied according to Dynamical Systems Theory (DST). -
Basic Analysis of a LOX/Methane Expander Bleed Engine
DOI: 10.13009/EUCASS2017-332 7TH EUROPEAN CONFERENCE FOR AERONAUTICS AND AEROSPACE SCIENCES (EUCASS) DOI: ADD DOINUMBER HERE Basic Analysis of a LOX/Methane Expander Bleed Engine ? ? ? Marco Leonardi , Francesco Nasuti † and Marcello Onofri ?Sapienza University of Rome Via Eudossiana 18, Rome, Italy [email protected] [email protected] [email protected] · · †Corresponding author Abstract As present trends in rocket engine development recommend overall simplicity and reliability as the main design driver, while preserving high performance, expander cycle engines based on the oxygen-methane pair have been considered as a possible upper stage option. A closed expander cycle is considered for Vega Evolution upper stage, while there are no studies published in the literature on methane-based expander bleed cycles. A basic cycle analysis is presented to evaluate the performance of an oxygen/methane ex- pander bleed cycle for an engine of 100 kN thrust class. Results show the feasibility of the system and its peculiarities with respect to the better known expander bleed cycle based on hydrogen. 1. Introduction The high chamber pressure required to achieve high specific impulse in liquid propellant rocket engines (LRE), has been efficiently obtained by pump-fed systems. Different solutions have been proposed since the beginning of space age and just a few of them has found its own field of application. In these systems the pumps are driven by gas turbines whose power comes from two possible sources: combustion or cooling system. The different needs for the specific applications (booster, sustainer or upper stage of different classes of rockets) led to classify pump-fed LRE systems in open and closed cycles, which differ because of turbine discharge pressure.14, 16 Closed cycles are those providing the best performance because the whole propellant mass flow rate is exploited in the main chamber.