A list of student topics for research that would be done at NASA Langley Research Center is listed below, by subject area. The first topic has funding available and we will be filling the positions as soon as a qualified student is found. The position is available for either Spring 2012 or Summer 2012. Interested students should apply immediately, even if their anticipated start date is Summer 2012. The remaining topics are ones where we anticipate the possibility of funding beginning Summer 2012 or Fall 2012. We anticipate adding additional subject areas throughout the year.

 

The National Institute of Aerospace (NIA) has an opening for a graduate student to work in the area of predicting jet noise fields in the presence of an airframe.  Selected candidate will work in collaboration with researchers in the Aeroacoustics Branch at NASA Langley Research Center in Hampton, VA. 
The noise from jet flows is an annoyance to the community, causes sonic fatigue on aircraft and rockets, and causes hearing loss for military and civilian personnel. The understanding, prediction, and mitigation of jet noise is an ongoing research effort for over sixty years at NASA. When jet engines are installed on air vehicles the noise from the jet plume is reflected and diffracted by the airframe. One method to predict this type of phenomenon is to use an acoustic analogy, which is a rearrangement of the governing equations of fluid dynamics into a left hand side operator and a right hand side equivalent source. The right hand side is separated into a term that controls the propagation and a term that represents the source of noise within the jet plume. The adjoint vector Green’s function of the linearized Euler equations controls the propagation of the jet noise from the source to the observer. This includes the refraction through the jet shear layer and the scattering by the airframe. The main goal of the project is to find the Green’s function of the linearized Euler equations and combine them with source models developed at NASA LaRC to find the scattered jet noise field. Validation of the methodology will be performed with existing experiments performed at NASA.

The objective of this project is to make predictions using the acoustic analogy for jet mixing noise with the computer program RANS Integration for Shock Noise (RISN) in the presence of airframe surfaces. Experiments performed at NASA Langley and NASA Glenn have been developed to validate the RISN code. These experiments involve large flat plates that represent simplified aircraft geometry with a jet plume near-by. The student will run the Fast Scattering Code (FSC) (download pdf at https://files.me.com/bernieg2/g9tazyhttps://files.me.com/bernieg2/g9tazy )and the modified Diffraction Integral Method 2 (DIM2) modified by NASA Langley to find the low and high frequency adjoint Green’s function of the convective wave equation. A matching function will be developed to match the low frequency and high frequency solutions at the mid frequencies from the result of FSC and DIM2. FSC and DIM2 solutions will contain the relevant geometry of the experiment. The matched adjoint Green’s function from FSC and DIM2 will be used as an argument in Lilley’s equation, which can be related in turn to the vector Green’s function of the linearized Euler equations.  The use of RISN and its associated acoustic analogies, in conjunction with the solutions of the Fully Unstructured Navier-Stokes (FUN3D) Computational Fluid Dynamics (CFD) solver, and the matched solutions of FSC and DIM2, will yield highly accurate predictions of the jet noise in the presence of an airframe.


Structural Mechanics: Bonded Joint and Progressive Damage Modeling Techniques 

The National Institute of Aerospace (NIA) has an opening for a graduate student to work in the area of predicting damage and delamination in advanced composite materials, and specifically bonded joint and progressive damage modeling techniques. Selected candidate will work in collaboration with researchers in the Structural Mechanics and Concepts Branch at NASA Langley Research Center in Hampton, VA. 
Successful candidate will support research to refine and validate current damage progression modeling techniques, to assess the scalability of these methods and adapt them as necessary for full-scale applications. Typical configurations of bonded joints will be considered, and the development of new formulations based on approaches such as fracture mechanics or cohesive zone models for modeling crack propagation will be conducted. The research is expected to provide a thorough understanding of the current applicability of detailed progressive damage modeling tools, and several tools for assessing and improving the accuracy of results performed at element and structure-level scales. The investigation will also aim at identifying the relevant material parameters required for a physically correct representation of the failure processes, and the validation will rely on a correlation with analytical and experimental data.

 

The National Institute of Aerospace (NIA) has an opening for at least two graduate students to work under the direction of Langley Professor Fuh-Gwo Yuan in the area of structures and materials, including, but not limited to: structural health management of metallic and composite structures, advanced materials and structures, multifunctional materials and structures, manufacturing and repair, and lightweight, flexible structures. Selected candidate will work in collaboration with researchers at NASA Langley Research Center in Hampton, VA. 

 
 

The National Institute of Aerospace (NIA) has an opening for a graduate student to work in the area of laser/ electro-optical sensors. The student should have a good background in electromagnetic theory with an emphasis on lasers and optics either in the visible or infrared spectrum.  Selected candidate will work in collaboration with researchers in the Electromagnetics and Sensors Branch at NASA Langley Research Center in Hampton, VA. 

The NASA Aviation Safety Program is interested in new techniques in advancing the detection of various kinetic air hazards such as wake vortex, clear air turbulence, icing conditions, volcanic ash, dry microburst, etc.  Research in this area is also focused on kinetic air hazards mentioned above using active and passive techniques for Aviation Safety.  There are research aspects that focus on the instrument itself and some that focus on the physics of the interaction of the electromagnetic wave with the aerosols, atmospheric gas constituents and particles of interest.


Electromagnetics:  Advanced Airborne Radar

The National Institute of Aerospace (NIA) has an opening for a graduate student to work in the area of advanced airborne radar. The student should have a good background in electromagnetic theory and applications in microwaves.  Selected candidate will work in collaboration with researchers in the Electromagnetics and Sensors Branch at NASA Langley Research Center in Hampton, VA. The NASA Aviation Safety Program is interested in new techniques in advancing the detection of various kinetic air hazards such as wake vortex, clear air turbulence, icing conditions, volcanic ash, dry microburst, etc.  Current research approaches include multi frequency radar, polarimetric radar and electronically scanning antenna arrays.  Airborne radar has more challenging constraints that do not exist in ground-based systems and these are taken into account.