National Aeronautics and Space Administration

Glenn Research Center

Research Projects

Behavior Characterization of Emerging Aero-Propulsion Materials

Project Team Members

Andrew Dianetti, Max Holliday, Peter Knapp

Principal Investigators

Susan Draper, Tim Gabb

1. Brief background & NASA mission/program support

Current and emerging commercial aircraft are utilizing advanced materials in propulsion components. Advanced Ni-base superalloys, designed to withstand higher temperatures to improve engine efficiency, are being utilized in compressor and turbine disks in current and emerging commercial aircraft. A turbine disk is a fracture critical structural engine component, as a failure usually results in a loss of engine, considerable airframe damage, and the possibility of loss of the aircraft. While the durability of these material systems was assessed during the material development and engine certification, safety issues can emerge as the new technologies accumulate time in service. High strength, high temperature disk alloys are susceptible to surface processing defects that have been known to cause failures. Work within the Vehicle Systems Safety Technology (VSST) project in the Aviation Safety Program addresses potential safety issues for recently implemented technologies as well as robust design for future emerging technologies.

2. Objective of project

The objective of the project will be to characterize Ni-base superalloys durability with an emphasis on effects of residual stresses, corrosion and oxidation on fatigue life. The students will work as a team with a mentor to analyze surface characteristics after corrosion and oxidation exposures. Pit size and density will be measured as a function of exposure conditions. The effect of surface condition and residual stresses on fatigue life will be documented by performing fatigue testing and fracture analysis.

3. Specific student team assignment

(a) Establish Team – Students will meet with the Ni-base Superalloy Disk research team to establish a plan, identify tasks, and establish responsibilities. Team meetings will be held on a regular basis to monitor progress.

(b) Research Techniques – Research related activities designed to gather materials related results could include metallography, optical microscopy, electron microscopy, chemical analyses, x- ray diffraction, mechanical testing, and quantitative microstructural analyses. The students will use established research techniques to perform corrosion characterization by measuring corrosion pit depth with an Alicona optical microscope and analyze corrosion products in the scanning electron microscope (SEM). Fatigue fracture surfaces will be analyzed on corroded and/or oxidized fracture samples using a SEM. Surface roughness measurements will be performed on shot-peened samples of turbine disk materials. Electropolishing and X-ray diffraction will be used to measure determine quantity and depth of surface residual stress for coated, shot-peened, and fatigue tested samples.

(c) The students will be expected to give an oral presentation summarizing the results and give recommendations. A NASA Technical Memorandum (TM) could be written based on the research results.

Aircraft Icing, Grid Generation, and CFD Analysis: How good is good enough?

Project Team Members

Daniel Oliden, Jun GaRam

Principal Investigators

Dr. Mark Potapczuk, Dr. Andy Broeren

1. Brief background & NASA mission/program support

NASA is developing tools for analysis and simulation of aircraft icing encounters as part of the Aviation Safety Program in the Aeronautics Research Mission Directorate. Of interest to NASA and to the aviation community is just how accurate these tools need to be to provide meaningful information for the icing analyst. Providing answers to the question, “How good is good enough?”, will provide guidance to the development of future engineering tools and to those using the tools for design and certification of aircraft for flight in icing conditions.

2. Objective of project

A computational study of the aerodynamic changes to an aircraft wing resulting from in-flight ice deposition on the leading edge will be the subject of the Aero Academy project. Existing computational tools will be used by the team to determine how much detail of the ice deposition geometry must be included in the analysis to produce an acceptably accurate determination of the changes to lift, drag, and pitching moment resulting from the presence of the ice. The team will perform parametric studies of these performance characteristics by varying the detail of the ice shape geometry, the fineness of the mesh used to simulate the flow, and the modeling methods employed for resolution of turbulent flow characteristics. The goal will be to determine just how good is good enough for engineering solutions to the problem and to therefore provide aircraft manufacturers with information that will aid in analysis of current and future vehicles.

3. Specific student team assignment

Students and mentors will meet to establish a plan and to identify roles and responsibilities. Each student will have an opportunity to provide leadership for the project by determining how the goals of their assignment introduce requirements into the overall project as well as how those requirements affect the scope and schedule of the project. The team should consist of students with an interest in aerodynamics, computational fluid dynamics, grid generation, CAD, and aircraft safety. The ideal team might consist of a PhD candidate, a Master’s degree student, and a Bachelor’s degree student. The PhD student and the Master’s degree student would be tasked with the CFD and aero analysis tasks. The Master’s degree student and the Bachelor’s degree student could work on the geometry modeling effort, consisting of the CAD and grid generation tasks.

All Electric Regional Transport Aircraft with Advanced Electric Motors, Power Management and Distribution, and Energy Storage

Project Team Members

Michael Romanko, Raul Rios, Rebecca Navarro, Nomita Vazirani

Principal Investigators

James Felder, Dr. Gerald Brown, Timothy Dever, and Jeff Berton

1. Brief background & NASA mission/program support:

A goal of research in the NASA Fundamental Aeronautics Program is to reduce the total mission energy consumption, noise reduction and oxides of nitrogen both during take-off and landing as well as during cruise for subsonic transport aircraft. Previous studies conducted by both NASA and industry have shown that within

25 years turboelectric propulsion, where turbine engines drive superconducting generators to create electrical power to drive superconducting motor driven propulsors, and hybrid electric propulsion, where turbine engines and electric motors driven by stored energy devices (batteries, flywheels, etc.) work in parallel and/or sequentially to drive propulsors, have the potential to propel transport aircraft with 150 to 300 seats over ranges from 3500 to 7500 nm, at cruise speeds from Mach 0.72 to 0.84 with substantial reductions in energy consumption, noise and emissions compared to current aircraft. On the other end of the time and size spectrum are light 2-seat aircraft that are already flying with current technology electric motors and batteries over short distances of approximately 100 nm. With anticipated advances in motor power density and battery energy storage density of nearly an order of magnitude greater than current devices there is the possibility of an all -electric transport aircraft that can move at least 50 passengers an economically viable distance using only stored energy. A team of student with support from several mentors with expertise in aircraft design and performance, aircraft propulsion, electric motor design, battery technology, flywheel technology, electrical power systems, thermal management and aircraft mission analysis will perform a conceptual design of a 50 seat regional aircraft of advanced design with an all-electric propulsion system using only stored electrical energy.

2. Objective of project

Determine the level of technology (power to weight and efficiencies of non-cryogenic, normal-conductor motor, energy storage energy density, etc.) that will be needed in order to allow an advanced technology regional aircraft of 50 passengers to fly at least a 500 nm mission using only stored electrical energy. There are no restrictions on propulsor type (straight or swept blade propeller or shrouded variable or fixed pitch fan) that can be used. In addition to thrust generation, stored energy can be used in ways or in devices that reduce drag (such as flow control devices or control surface blowers to reduce control surface area). The energy storage pack used must have sufficient power capacity during recharge that it can be recharged within 45 minutes without removal from the aircraft. The total mission energy includes any losses during charging. Noise is not a primary driver, but should also be considered at least qualitatively. Cruise speed and field length are not set, but should be competitive with current 50-70 seat commuter aircraft such as the Bombardier Q-400.

3. Specific students team assignment

a) Establish Team- Students and mentors will meet to establish a plan, identify roles, and responsibilities.

b) Research potential technologies that can increase motor power density and energy storage density to determine what is considered by NASA and other researchers as being the “least-expected”, “most likely”, and “max-anticipated” values for power or energy density and efficiency for each propulsion subsystem.

c) Create a conceptual 50 seat commuter aircraft design with an assumed “most-likely” value of the weight, volume and overall efficiency of the propulsion system components and determine the range max power and mission power and energy profile. The aircraft design should represent a design with all the aircraft technologies anticipated in the same timeframe assumed for the propulsion system. The demands of the novel propulsion system will require equally novel approaches to aircraft configurations in order to place the energy storage packs in an efficient aerodynamic shape. The team will brainstorm potential configurations and then select one or two to refine further.

d) Collectively iterate the design of the aircraft and propulsion system with each person on the team updating their portion of the design until the design converges.

e) If the calculated range is less than 500 nm repeat the analysis for the max-anticipated values. If the range is greater than 500 nm repeat the analysis for the least-expected values. If time permits repeat for both the least-expected and max-anticipated sets of values.