Propulsion and Power Commons^™

Noise And Propulsive Efficiency Interactions For Rotors And Propellers At Constant Thrust, Riccardo Roiati

Doctoral Dissertations and Master's Theses

In the emerging market of Advanced Air Mobility (AAM), aerospace companies have been designing and prototyping electric and hybrid vehicles to revolutionize travel. These vehicles must have low noise and particulate emissions while also having enough propulsive efficiency to complete the mission. This thesis aims to study the relationship between noise and propulsive efficiency as related to any aircraft equipped with an electric motor and a variable pitch rotor/propeller. The combination of the electric motor with the variable pitch propeller/rotor allows for a decoupled rotational speed and torque generation, meaning that the electric motor can generate the same amount of …

Quasi 1d Modelling Of A Scramjet Engine Cycle Using Heiser-Pratt Approach, Asmaa Chakir

Theses and Dissertations

Scramjet engines are key for sustained hypersonic flights. Analytic models play a critical role in the preliminary design of a scramjet engine configuration. The objective of this research is to develop and validate a quasi-1D model for the scramjet engine encompassing inlet, isolator and combustor, to evaluate the impact of flight conditions and design parameters on the engine functionality. The model is developed assuming isentropic flow in the inlet with a single turn; modified Fanno-flow equations in the isolator that account for the area change of the core flow; and the combustor is modeled using Heiser-Pratt equations accounting for the …

The Design And Development Of A Miniature Gridded Ecr Ion Thruster, Nicholas Nuzzo

Masters Theses

Plasma propulsion, a specific subset of electric propulsion (EP), is a class of space propulsion that produces plasma by excitation of a propellant at or above its ionization energy. This ionized propellant is then accelerated by an externally applied field (magnetic and/or electric) and produces thrust. There is an increasing need for miniaturization in spacecraft technology and the use of plasma EP devices in space propulsion. These systems provide an advantage over traditional chemical propulsion solutions which are less efficient and have more mass. Miniaturization of EP devices allows missions to have more space and mass available for their payloads …

2022 Summer-Fall Graduate Recognition Program, Propulsion Research Center, Robert Frederick

PRC Graduate Recognition

This program includes the graduate recognition program for summer and fall 2022. Includes photographs, upcoming events, recent publications, and student profiles.

Spacecraft Systems & Navigation, Christopher Vanacore

Student Works

This textbook is steered towards higher educational course entailed in Commercial Space Operations. This textbook will be covering in detail Orbital Satellites, and Spacecraft. These topics are discussed according to their application, design, and environment. The power system, shielding and communication systems are reviewed along with their missions, space, environment and limitations. Any vehicle, whether manned or unmanned, intended for space travel is a spacecraft. A spacecraft's required systems and equipment depend on the information it will acquire and the tasks it will perform. Although their levels of sophistication vary widely, they re all subject to the harsh conditions of …

Application Of Direct Feedback Tunable Diode Laser Absorption Spectroscopy Within A Hybrid Rocket Combustor, Connor Becnel

LSU Master's Theses

With interest in space travel and space-related science increasing in recent years, significant efforts to reduce the cost and increase the safety of rocket motors have become commonplace. Liquid rockets are currently the most commonly used system, but there is interest in the reduced complexity of hybrid rockets. For these hybrid rocket motors to become the norm, extensive research on their complex boundary layer combustion needs to be performed. Modeling these hybrid systems is of much interest to companies developing rocket motors; ultimately, small-scale experiments will help validate their behavior. This paper covers the application of a near-infrared tunable diode …

Seal For A Wave Rotor Disk Engine, Christopher Tait, Pejman Akbari, Brian Sell, Marc D. Polanka

AFIT Patents

A unique seal for a wave rotor disk engine is disclosed herein. The seal is operable for sealing a region between a rotor and a rotor casing. The seal is spring loaded and will engage with the tip of the rotor to reduce pressure loss within the wave rotor disk engine.

Impulse Measurement Methods For Pulsed Laser Ablation Propulsion, Ishaan Mishra, Scott Kirkpatrick

Rose-Hulman Undergraduate Research Publications

Pulsed laser ablation propulsion has the potential to revolutionize space exploration by eliminating the requirement of a spacecraft to carry its propellant and power source as the high-power laser is situated off-board. More experimentation needs to be done to optimize this propulsion system and understand the mechanisms of thrust generation. There are many methods used to calculate the impulse imparted in pulsed laser ablation experiments. In this paper, key performance parameters are derived for some of the impulse measurement methods used in ablation propulsion experiments. Regimes discussed include the torsional pendulum system, simple pendulum system, and solid and liquid microspheres.

A Comparative Performance Analysis Of The Novel Turboaux Engine With A Turbojet Engine, And A Low-Bypass Ratio Turbofan Engine With An Afterburner, Kaleab Fetahi, Sharanabasaweshwara A. Asundi, Arthur C. Taylor

Mechanical & Aerospace Engineering Faculty Publications

Presented herein is a comparative performance analysis of a novel turbofan engine with an auxiliary combustion chamber, nicknamed the TurboAux engine, against a turbojet engine, and a low bypass ratio turbofan engine with an afterburner is presented. The TurboAux engine is an adaption of the low-bypass ratio turbofan engine, but with secondary combustion in an auxiliary bypass annular combustion chamber for thrust augmentation. The TurboAux engine is envisioned with the desire to facilitate clean secondary burning of fuel at temperatures higher than in the main combustion chamber with air exiting the low-pressure compressor. The comparative study starts by analyzing the …

Feasibility Of Low-Enriched Uranium Fueled Nuclear Thermal Propulsion In The Low-Thrust Region Below 16klbf, Samantha B. Rawlins, Dale L. Thomas

PRC-Affiliated Research

No abstract provided.

Turbine Cooling System With Energy Separation, James L. Rutledge, Matthew Fuqua, Carol M. Bryant

AFIT Patents

A method and system for cooling an engine and/or vehicle using energy separation is disclosed herein. An energy separation device is operable for separating a compressed gaseous coolant stream into a first relatively cooler coolant flow stream and a second relatively hotter coolant flow stream. The relative cooler coolant flow stream is directed to a first region requiring increased cooling and the relative hotter coolant flow stream is directed to a second region requiring lower cooling than the first region in the engine or vehicle.

Disk Engine With Circumferential Swirl Radial Combustor, Brian Bohan, Marc Polanka, Bennett Staton

AFIT Patents

A disk engine and system configured to provide high power at a reduced axial length is disclosed herein. The disk engine includes a radial compressor, a compressor discharge manifold positioned circumferentially about compressor, a combustion chamber positioned within the discharge manifold and a radial turbine positioned radially inward of the combustion chamber.

Controller Platform Design And Demonstration For An Electric Aircraft Propulsion Driv, Rosten Sweeting

Graduate Theses and Dissertations

With the growth in the aerospace industry there has been a trend to optimize the performance of an aircraft by reducing fuel consumption and operational cost. Recent advancements in the field of power electronics have pushed towards the concepts of hybrid electric aircraft also known as more electrical aircrafts. In this work, a custom controller board for an electric aircraft propulsion drive was designed to drive a permanent magnet synchronous motor. Design of the controller board required knowledge of the topology selection and power module selections. Simulations of the system were performed using MATLAB/Simulink to analyze the overall performance of …

Performance Study Of Post-Processed Additively Manufactured Low Thrust Nozzles, Tyler W. Gerhold

Theses and Dissertations

This research explores metal post-processing techniques to effectively reduce the large anomalous protrusions found in small additively manufactured low thrust rocket nozzles. Research has found that nozzles of this kind can experience losses in thrust of over 40%. Analytic theory of adiabatic nozzle flow with viscous losses for additively manufactured nozzles does not align with what has been found when tested experimentally. Compressible flow losses, such as shock wave formation inside the nozzle diverging cone, are likely the leading causes of such loss. Reduction in nozzle irregularities can likely yield results seen in analytic theory with similar performance to traditional …

Method And Simulation Of On-Orbit Sub-Microthrust Evaluation, Jonathan Hood

Master's Theses

With the advent of smaller satellites, along with the need for less than 0.1 μN precision attitude control for interferometry and imaging missions, finer micro- to sub-micro- thrusters have become an area of high interest. As thrusters are developed and ground-tested, it is necessary to evaluate their thrust performance on-orbit. On-orbit measurements offer actual thrust performance in mission conditions, free from ground facility vibrations and miniaturization restraints, and allow a thruster system to achieve a NASA Technology Readiness Level (TRL) of 7-8. A review is conducted of existing and proposed ground and on-orbit thrust measurement techniques. Experimental gaps and complementary …

Direct Simulation And Reduced-Order Modeling Of Premixed Flame Response To Acoustic Modulation, Zheng Qiao

Theses and Dissertations

This dissertation introduces a general, predictive and cost-efficient reduced-order modeling (ROM) technique for characterization of flame response under acoustic modulation. The model is built upon the kinematic flame model–G-equation to describe the flame topology and dynamics, and the novelties of the ROM lie in i) a procedure to create the compatible base flow that can reproduce the correct flame geometry and ii) the use of a physically-consistent acoustic modulation field for the characterization of flame response. This ROM addresses the significant limitations of the classical kinematic model, which is only applicable to simple flame configurations and relies on ad-hoc models …

Using An Ultrasonic Technique To Determine Burning Rate Law, Brennan Hatton Haralson

Honors Capstone Projects and Theses

No abstract provided.

Performance Variability In Solid Rocket Motors, Manvith Amara

Honors Capstone Projects and Theses

No abstract provided.

2022 Spring Graduate Recognition Program, Propulsion Research Center, Robert Frederick

PRC Graduate Recognition

This program includes the graduate recognition program for spring 2022. Includes photographs, upcoming events, recent publications, and student profiles.

Rotating Detonation Rocket Engine Fluidic Diode Injector Studies, Allison Brooke Lentz

Honors Capstone Projects and Theses

No abstract provided.

Computational Comparison Of Dual Bell, Expansion-Deflection, And Aerospike Nozzles, Manuel R. Abadie Ardon

Honors College Theses

In the search for a Single-Stage-to-Orbit rocket, Altitude Compensating Nozzles concepts (ACNs) have been proposed since the 1950s, but research has stalled despite the modern analysis tools available. These nozzle concepts offer optimum performance at two or more altitude settings. This research chose three of these concepts, these being the Dual Bell, Expansion-Deflection, and Aerospike, which were designed and analyzed at various pressure ratios (NPR=10,15,30,36,30,45) using Computational Fluid Dynamics (CFD) software FLUENT. Simulations generated pressure distributions along the nozzle wall, which allowed to calculate data values such as thrust coefficients. Nozzle efficiency is calculated from this data and used to …

Understanding The Nonlinear Dynamics Governing Vertical-Lift Vehicles With Variable-Speed, Fixed Rotors, Stephanie Vavra, Micah Busboom, Aleea Stanford, Keegan Moore

UNL Student Research Days Posters, Undergraduate

Problem: Traffic significantly limits travel in urban areas. • The NASA Urban Air Mobility Project is developing an air taxi as an alternative mean of transportation (Fig. 1).

Challenge: Operating rotors at different frequencies may cause the cabin to vibrate at high amplitudes. Such effects are currently unknown.

Objective: Understand the effect of variable speed rotors on passenger comfort.

From the reduced-order modeling simulations, it can be assumed that counteracting the rotor speed in-balances can reduce the displacement and vibrations experienced at the center of the wing. In other words, should a rotor not maintain its optimal operation speed, reducing …

Cfd Simulation Of Varying Fuel Jet Placement Of Mach 2 Flow (Paper), Sara Broad

Honors Capstone Projects

Supersonic flow is a concept that has been researched heavily for the past twenty years. It has many applications, with the most notable one being for the defense industry. This project specifically is based off a model that is being currently used for Air Force research. With supersonic flow, where the Mach number is larger than one, there has been continual research specifically on flameholders. Flameholders involve the discussion of the mixing, ignition, and combustion of the fuel that is released into the lower cavity of the scramjet. There is a current standard for the placement of fuel jets, but …

Investigation Of The Low-Temperature Combustion Phenomena Of A Fischer-Tropsch Synthetic Aerospace Fuel In A Constant Volume Combustion Chamber For Greenhouse Gas Reduction, Lily H. Parker

Honors College Theses

Greenhouse gases (GHG) have a harmful effect on our environment as they trap heat in the atmosphere accelerating climate change. As such, the Federal Aviation Administration’s 2025 strategic plan to reduce GHG emissions from air transportation. This call to action for a more environmentally friendly option highlights the importance of synthetic fuels as they are more sustainable compared to traditional fossil fuels. An investigation was conducted into the thermal-physical properties of Synthetic Fischer-Tropsch (F-T) Sustainable Aviation Fuels (SAF) and the Low Temperature Combustion (LTC). LTC is composed of the Low Temperature Heat Release (LTHR) and Negative Temperature Coefficient (NTC) region, …

Manufacturing Of A Ceramic Turbine Rotor For A Compact Jet Engine, Bryan T. Leicht

Theses and Dissertations

The primary goal of this study was to develop a low-cost, timely, scalable manufacturing method that produced a ceramic turbine that can be tested as a drop-in replacement on a JetCat P400 small scale gas turbine engine. This research compared two processes for manufacturing a ceramic turbine utilizing a pour casting method and 3D printing using stereolithography ceramic manufacturing (SLCM). The pour casting method used Silicon Nitride to create a cast turbine using a sacrificial 3D printed mold. The SLCM method evaluated producing an alumina turbine using an ADMATEC Admaflex 300 SLCM printer to directly print a ceramic turbine. This …

Design And Application Of Compact Combustors In Small-Scale Jetcat Engines, Nathan A. Clark

Theses and Dissertations

Ultra-compact combustors (UCC) are an innovative approach to improving overall engine efficiency and thrust-to-weight ratio by reducing the axial length and weight of the engine. Previous efforts looked at integrating a UCC into a small-scale JetCat P90 engine utilizing gaseous propane fuel. The current investigation aimed to utilize the previous compact combustor design and switch fuels to liquid kerosene. Based on the results from testing, a new combustor was designed equipped with a different flame holding mechanism at the larger P400-scale while maintaining a length savings of 20%. Testing of the P400 compact combustors was performed within a newly designed …

Design Of An Electro-Thermal Nanosatellite Propulsion System, James H. Founds

Theses and Dissertations

This research focused on designing an arcjet system with water as the propellant. Previous research developed a compact, reliable, and safe propellant storage and feed system. The goal is to combine the arcjet with the previous tank to achieve thrust and specific impulse characteristics greater than cold gas or resistojet system. This platform features a 1 U, non-hazardous, and sub-kilowatt powered propulsion system for nanosatellites. A simplified analysis of the design predicts thrust and specific impulse greater than can be achieved by cold gas or resistojet thrusters. Testing resulted in oxidation of the electrodes raising concerns about the longevity of …

Flow And Heat Transfer Characteristics In A Pre-Swirl Rotor-Stator Cavity, Xiaoyu Yang, Zhong Ren, Jing Ren, Philip M. Ligrani

PRC-Affiliated Research

The present study investigates flow and heat transfer characteristics in a rotor-stator pre-swirl system. Considered are rotational Reynolds numbers ReФ ranging from 3.4 × 105 to 6.8 × 105, with jet Reynolds numbers Rew of approximately 8.8 × 104 to 3.81 × 105, and associated turbulent flow parameter λT = Cw/ReФ0.8 varying from 0 to 0.4. Experimentally-measured and numerically-predicted results illustrate the combined and separate influences of jet impingement and rotor entrainment, as they affect and govern flow and heat transfer characteristics within the cavity. These results show that the relative strength of the two effects varies with ReФ and …

Analysis Of Nozzle Expansion Characteristics In Supersonic Retro-Propulsion, Gonzalo Montoya

Honors Undergraduate Theses

Supersonic retro-propulsion (SRP) is defined as rocket propulsion used to decelerate aerospace vehicles at supersonic speed. SRP is often used as a method of high-speed deceleration on space vehicles. The main method of propulsion used in the application of SRP is rocket propulsion. Rocket engine thrust and performance changes with altitude and expansion ratio. Changing altitudes across the trajectory of a rocket affect how the exhaust plume shock waves expand. Being able to identify how different expansion ratios affect the exhaust plume flow fields would provide useful data on how SRP performance can be predicted. This research projects aims at …

Extreme-Pressure Ignition Studies Of Methane And Natural Gas With Co2 With Applications In Rockets And Gas Turbines, Cory Kinney

Electronic Theses and Dissertations, 2020-2023

Although concerns about carbon dioxide (CO2) emissions and their impact on climate change has led to an increase in renewable energy electricity generation, natural gas power plants remain the dominant source of electricity generation in the United States. Until the capacity of renewable energy sources can meet growing electricity demand, natural gas power generation will likely remain an important source of electricity generation. Supercritical CO2 (sCO2) power generation cycles offer an alternative to traditional gas turbines by reusing and sequestering CO2 from the combustion process to prevent its release into the atmosphere. This study seeks to understand natural gas ignition …