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DOE OSTI2020

Cybersecurity Vulnerability Mitigation Framework through Empirical Paradigm: Enhanced Prioritized Gap Analysis

Existing cybersecurity vulnerability assessment tools were designed based on the policies and standards defined by organizations such as the U.S. Department of Energy and the National Institute of Standards and Technology (NIST). Frameworks such as the cybersecurity capability maturity model (C2M2) and the NIST Cybersecurity Framework (CSF) are often used by the critical infrastructure owners and operators to determine the cybersecurity maturity of their facility. Although these frameworks are exceptional at performing qualitative cybersecurity analysis and identifying vulnerabilities, they do not provide a means to perform prioritized mitigation of those vulnerabilities in order to achieve a desired cybersecurity maturity. To address that challenge, we developed a framework and software application called the cybersecurity vulnerability mitigation framework through empirical paradigm (CyFEr). This paper presents the detailed architecture of CyFEr’s enhanced prioritized gap analysis (EPGA) methodology and its application to CSF. The efficacy of the presented framework is demonstrated by comparing against existing similar models and testing against the cyber injects from a real-world cyber-attack that targeted industrial control systems (ICS) in critical infrastructures.

Gourisetti, Sri Nikhil G.↗

DOE OSTI2022

Effectiveness of Privacy Techniques in Smart Metering Systems

Smart grid technologies enable timely energy billing for residential homes. The ability to react to energy demands during peak hours allows energy providers to conserve power and operate efficiently. However, these data streams are also susceptible to privacy attacks within the energy company and from outside hackers. We implemented four different privacy models: k-anonymous, l-diversity, t-closeness, and ε-differential privacy. We demonstrate the models’ effectiveness using a real-world dataset composed of 15 different residential households with energy consumption data spanning over a year.

Peralta-Peterson, Martin↗

DOE OSTI2025

Differentially Private Adaptive Noise Injection (DP-ANI) v1.0

Location data is collected from users continuously to understand their mobility patterns. Releasing the user trajectories may compromise user privacy. Therefore, the general practice is to release aggregated location datasets. However, private information may still be inferred from an aggregated version of location trajectories. Differential privacy (DP) protects the query output against inference attacks regardless of background knowledge. This software implements a differential privacy-based privacy model that protects the user's origins and destinations from being inferred from aggregated mobility datasets. This is achieved by injecting Planar Laplace noise to the user origin and destination GPS points. The noisy GPS points are then transformed into a link representation using a link-matching algorithm. Finally, the link trajectories form an aggregated mobility network. The injected noise level is selected using the Sparse Vector Mechanism. This DP selection mechanism considers the link density of the location and the functional category of the localized links. Compared to the different baseline models, including a k-anonymity method, our differential privacy-based aggregation model offers query responses that are close to the raw data in terms of aggregate statistics at both the network and trajectory-levels with maximum 9% deviation from the baseline in terms of network length.

Peisert, Sean [Lawrence Berkeley National Laborato↗

DOE OSTI2020

Resiliency of Degraded Built Infrastructure

Infrastructure resiliency depends on the ability of infrastructure systems to withstand, adapt, and recover from chronic and extreme stresses. In this white paper, we address the resiliency of infrastructure assets and discuss improving infrastructure stability through development of our understanding of cement and concrete degradation. The resiliency of infrastructure during extreme events relies on the condition, adaptability, and recoverability of built infrastructure (roads, bridges, dams), which serves as the backbone of existing infrastructure systems. Much of the built infrastructure in the US has consistently been rated D+ by the American Society of Civil Engineers (ASCE). Aged infrastructure introduces risk to the system, since unreliable infrastructure increases the likelihood of failures under chronic and extreme stress and are particularly concerning when extreme events occur. To understand and account for this added risk from poor infrastructure quality, more research is needed on (i) how the changing environment alters the aging of new and existing built infrastructure and (ii) how degradation causes unique failure mechanisms. The aging of built infrastructure is based on degradation of the structural materials, such as concrete and steel supports, which causes failure. Current work in cement/concrete degradation is based on (i) the development of high strength and degradation resistance concrete mixtures, (ii) methods of assessing the age and reliability of existing structures, and (3) modeling of structural stability and the microstructural evolution of concrete/cement from degradation mechanisms (sulfide attack, carbonation, decalcification). Sandia National Laboratories (SNL) has made several investments in studying the durability and degradation of cement based materials, including using SNL-developed codes and methodologies (peridynamics, PFLOTRAN) to focus on chemo-mechanical fracture of cement for energy applications. Additionally, a recent collaboration with the University of Colorado Boulder has included fracture of concrete gravity dams, scaling the existing work to applications in full sized infrastructure problems. Ultimately, SNL has the experience in degradation of cementitious materials to extend the current research portfolio and answer concerns about the resilience of aging built infrastructure.

36 MATERIALS SCIENCE↗

NASA NTRS1972

Supersonic aerodynamic characteristics of a lifting-body orbiter model with a blunted delta planform at Mach 2.30 to 4.60

An investigation has been made in the Langley Unitary Plan wind tunnel to determine the aerodynamic characteristics of a lifting-body orbiter model with a blunted delta planform. The model was tested at Mach numbers from 2.30 to 4.60, at nominal angles of attack from -4 deg to 60 deg and angles of sideslip from -4 deg to 10 deg, and at a Reynolds number of 2.5 million per foot.

Blair, A. B., Jr.↗

NASA NTRS1973

Aerodynamic characteristics of a 55 deg clipped-delta-wing orbiter model at Mach numbers from 1.60 to 4.63

Wind tunnel tests to determine the supersonic aerodynamic characteristics of a delta wing space shuttle orbiter model were conducted. The model was tested at Mach numbers from 1.60 to 4.63, at nominal angles of attack from minus 2 degrees to plus 30 degrees, nominal sideslip angles of minus 4 degrees to plus 10 degrees, and Reynolds numbers from 1.8 to 2.5 times one million per foot.

Blair, A. B., Jr.↗

NASA NTRS1973

Hypersonic aerodynamic characteristics of an all-body research aircraft configuration

An experimental investigation was conducted at Mach 6 to determine the hypersonic aerodynamic characteristics of an all-body, delta-planform, hypersonic research aircraft (HYFAC configuration). The aerodynamic characteristics were obtained at Reynolds numbers based on model length of 2.84 million and 10.5 million and over an angle-of-attack range from minus 4 deg to 20 deg. The experimental results show that the HYFAC configuration is longitudinally stable and can be trimmed over the range of test conditions. The configuration had a small degree of directional stability over the angle-of-attack range and positive effective dihedral at angles of attack greater than 2 deg. Addition of canards caused a decrease in longitudinal stability and an increase in directional stability. Oil-flow studies revealed extensive areas of separated and vortex flow on the fuselage lee surface. A limited comparison of wind-tunnel data with several hypersonic approximations indicated that, except for the directional stability, the tangent-cone method gave adequate agreement at control settings between 5 deg and minus 5 deg and positive lift coefficient. A limited comparison indicated that the HYFAC configuration had greater longitudinal stability than an elliptical-cross-section configuration, but a lower maximum lift-drag ratio.

Clark, L. E.↗

NASA NTRS1974

Numerical simulation of high Reynolds number transonic flows

A code has been developed for simulating high Reynolds number transonic flow fields of arbitrary configuration. An explicit finite-difference method with time splitting is used to solve the time-dependent equations for compressible turbulent flow. A nonorthogonal computational mesh of arbitrary configuration facilitates the description of the flow field. The code is applied to simulate the flow over an 18 percent thick circular-arc biconvex airfoil at zero angle of attack and free-stream Mach number of 0.775. A simple mixing-length model is used to describe the turbulence and chord Reynolds numbers of 1, 2, 4, and 10 million are considered. The solution describes in sufficient detail both the shock-induced and trailing-edge separation regions, and provides the profile and friction drag.

Deiwert, G. S.↗

NASA NTRS1975

Flow visualization study of close-coupled canard wing and strake wing configuration

The Langley 1/8-scale V/STOL model tunnel was used to qualitatively determine the flow fields associated with semi-span close coupled canard wing and strake wing models. Small helium filled bubbles were injected upstream of the models to make the flow visible. Photographs were taken over the angle-of-attack ranges of -10 deg to 40 deg.

Miner, D. D.↗

NASA NTRS1975

Results of investigations on the 0.004-scale model 74-0 of the configuration 4 (modified) space shuttle vehicle orbiter in the NASA/MSFC 14-by-14-inch trisonic wind tunnel (oa131)

The results of an oil flow boundary-layer visualization wind tunnel test of an 0.004-scale model of the Space Shuttle Vehicle Orbiter in the NASA/Marshall Space Flight Center 14-by-14-inch Trisonic Wind Tunnel are presented. The model was tested at Mach numbers from 0.60 through 2.75, at angles-of-attack from 0 through 25 degrees, and at unit Reynolds numbers from 5.0 to 7.0 million per foot. The test program involved still and motion picture photography of oil-paint flow patterns on the orbiter, during and immediately after tunnel flow, to determine areas of boundary layer separation and regions of potential auxiliary power unit exhaust recirculation during transonic and low supersonic re-entry flight.

Nichols, M. E.↗

NASA NTRS1976

Force test of a 0.88 percent scale 142-inch diameter solid rocket booster (MSFC model number 461) in the NASA/MSFC high Reynolds number wind tunnel (SA13F)

The results are presented of a force test of a .88 percent scale model of the 142 inch solid rocket booster without protuberances, conducted in the MSFC high Reynolds number wind tunnel. The objective of this test was to obtain aerodynamic force data over a large range of Reynolds numbers. The test was conducted over a Mach number range from 0.4 to 3.5. Reynolds numbers based on model diameter (1.25 inches) ranged from .75 million to 13.5 million. The angle of attack range was from 35 to 145 degrees.

Johnson, J. D.↗

NASA NTRS1979

Results of transonic tests in the NASA/MSFC 14-inch trisonic wind tunnel on a 0.004-scale model (74-OTS) space shuttle launch vehicle (FA25)

The primary objective of the test was to determine the aerodynamic increments due to the attach structure. Secondary objectives were to determine the effects of: (1) orbiter nose mold line changes; (2) wire bundle fairings on data measurements; and (3) flow angularity. The scale model was tested over the Mach range from 0.60 to 1.25 at angles of attack and sideslip from -8 to +8 deg. The total pressure was 22 psia for all runs. Six-component orbiter data were obtained from a balance in the orbiter which was sting supported. The external tank was attached to the solid rocket booster, each of which was sting supported. An alternate two sting/two balance arrangement was also tested with a single sting and balance in the external tank measuring combined ET/SRB aero data replacing the two stings in the SRB's. Two runs were also made at Mach number 4.96 with the two SRB's removed. The aerodynamic coefficients obtained are tabulated as a function of angle of attack or sideslip for each Mach number value.

Lundy, T. E.↗

NASA NTRS1980

A computational and experimental study of high Reynolds number viscous/inviscid interaction about a cone at high angle of attack

The flow over a 5 deg semi-angle cone at incidence in supersonic flow is studied as a model problem for the flow over aircraft forebodies. A computational method utilizing the conically symmetric Navier-Stokes equations is used to obtain theoretical flow results which are compared with experimental data from the Ames Research Center 6- by 6-Foot Wind Tunnel and with results from a cone model sting mounted on an F-15 aircraft. The computed results agree well with the wind-tunnel data but less well with the flight data. Modification of the algebraic turbulence model was necessary to reflect an apparent lower turbulence level in flight than was present in the wind tunnel.

Mcrae, D. S.↗

NASA NTRS1980

Linear analysis of poststall gyrations

The poststall gyrations of a high-performance aircraft are investigated by approximating the equations of motion with a linear mathematical model. Equilibrium poststall spin conditions are determined, which are not limited to small angles or spin rates and are used as reference conditions about which the linear model is developed. As a result, complete coupling between lateral and longitudinal motions is retained. Three aerodynamic models are evaluated using this linear analysis. These models include pure rotary derivatives obtained from VPI&SU stability tunnel, forced-oscillation data obtained from NASA tests, and a combination of the two which separates the unsteady and pure rotary derivatives. Results indicate that this last model gives better predictions of aircraft motion during poststall gyrations at high angles of attack and large sideslip angles. Comparisons are made with full-scale flight test results.

Hreha, M. A.↗

NASA NTRS1958

Correlations Among Ice Measurements, Impingement Rates Icing Conditions, and Drag Coefficients for Unswept NACA 65A004 Airfoil

An empirical relation has been obtained by which the change in drag coefficient caused by ice formations on an unswept NACA 65AO04 airfoil section can be determined from the following icing and operating conditions: icing time, airspeed, air total temperature, liquid-water content, cloud droplet impingement efficiencies, airfoil chord length, and angles of attack. The correlation was obtained by use of measured ice heights and ice angles. These measurements were obtained from a variety of ice formations, which were carefully photographed, cross-sectioned, and weighed. Ice weights increased at a constant rate with icing time in a rime icing condition and at progressively increasing rates in glaze icing conditions. Initial rates of ice collection agreed reasonably well with values predicted from droplet impingement data. Experimental droplet impingement rates obtained on this airfoil section agreed with previous theoretical calculations for angles of attack of 40 or less. Disagreement at higher angles of attack was attributed to flow separation from the upper surface of the experimental airfoil model.

Gray, Vernon H.↗

NASA NTRS1985

Evaluation of a stalled airfoil analysis program

The Stalled Airfoil Analysis Program (SAAP) is a computer code for predicting the aerodynamic characteristics of an airfoil up to, and beyond, stall. SAAP is presently evaluated through comparisons with experiments and with two other theoretical methods over an extensive range of airfoils and Reynolds number conditions. SAAP modeled drag more accurately than either of the other methods, and at angles of attack below stall yielded a smoother lift variation with angle of attack.

Rumsey, C. L.↗

NASA NTRS1987

Two-dimensional aerodynamic characteristics of the AMES HI-120, HI-8, and LOW-12 airfoils

During the period between June and September 1986, the Aeronautical and Astronautical Engineering Research Laboratory (AARL) at the Ohio State University (OSU) in Columbus, Ohio, conducted tests in the 6"X22" Transonic Blowdown Wind Tunnel to determine the two-dimensional lift, drag, and pitching moment coefficients for three airfoils designated AMES HI-120, AMES LOW-12, and AMES HI-8. These tests covered a Mach number range of 0.20 to 0.86, Reynolds numbers between 2 x 10 to the 6th and 6 x 10 to the 6th powers, and angles of attack between 0 and 13 degs as directed by the NASA Project Engineer; each model was not run at every condition. This work was performed under NASA Grant NAG-2-401, Analysis of Two Advanced Transonic Airfoils.

Gregorek, G. M.↗

NASA NTRS1987

Theoretical approach to oxygen atom degradation of silver

Based on available Rutherford backscattering spectrometry (RBS), proton induced X-ray emission (PIXE) and ellipsometry data obtained on silver specimens subjected to atomic oxygen attack in low Earth orbit STS flight 41-G, a theory was developed to model the oxygen atom degradation of silver. The diffusion of atomic oxygen in a microscopically nonuniform medium is an essential constituent of the theory. The driving force for diffusion is the macroscopic electrochemical potential gradient developed between the specimen surface exposed to the ambient and the bulk of the silver specimen. The longitudinal electric effect developed parallel to the gradient is modified by space charge of the diffusing charged species. Lateral electric fields and concentration differences also exist due to the nonuniform nature of the medium. The lateral concentration differences are found to be more important than the lateral electric fields in modifying the diffusion rate. The model was evaluated numerically. Qualitative agreement exists between the kinetics predicted by the theory and kinetic data taken in ground-based experiments utilizing a plasma asher.

Fromhold, Albert T., Jr.↗