Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 749.96K | Year: 2015
In Phase I, a prototypical FUN3D-based ZONA Euler Unsteady Solver (FunZEUS) was developed to generate the Generalized Aerodynamic Forces (GAFs) due to structural modes, control surface kinematic modes, and gust excitation using a frequency-domain linearized unstructured Euler solver based on the Navier-Stokes solution of FUN3D as the steady background flow. These GAFs can lead to a state-space equation representing the plant model for rapid aeroelastic and aeroservoelastic (ASE) design and analysis. The overall technical objective of Phase II is to develop and validate a production-ready FunZEUS that will be developed by enhancing the prototypical FunZEUS (1) to drastically improve its computational efficiency; (2) to expand its commercialization potential by interfacing with other commercial CFD codes; (3) to include the static aeroelastic effects in the GAF generation; (4) to demonstrate its applicability to complex configurations; (5) to showcase its plant model generation capability using spoilers and other control surfaces; and (6) to improve its maintainability and modularity by integrating all modules in a ZONA's database and dynamic memory management system.
Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase I | Award Amount: 149.91K | Year: 2012
ABSTRACT: The ability to ascertain rapid and accurate aeroelastic system stability margin as well as the ability to extract flight test structure mode shapes for on-the-fly investigation of aero-structure interactions are some of the real challenges facing control room engineers during flight testing of aircraft. The proposed developments in this Proposal aim to meet these challenges through the application of a non-linear system identification methodology applied to uncoupled single-degree-of-freedom generalized modal coordinates (GMC) used to identify aeroelastic stability via application of the Hilbert Transformation (HT) and a Covariance-Driven Stochastic Subspace (CDSS) approach to extract flight test structure mode shapes. ZONA Technology, Inc. will extend its commercially available ZONA Aeroelastic Model Simulator (ZAMS) product under the IADS flight test display environment and build upon its framework to establish new IADS displays that will clearly address these challenges. The proposed IADS displays will provide real time display of: (1) flight test derived and analytical overlaid mode shapes, (2) aeroelastic system frequency and damping time histories, (3) an aeroelastic system damping meter, and (4) modal participation plot. Two successful proof-of-concept studies based on these methods have been conducted. Once developed, these toolsets will significantly enhance the flight test control rooms decision making capability through better gauging of aircraft stability. BENEFIT: The proposed research and development effort will enhance flight test control room personnel's capability to gauge the flight test aircraft aeroelastic stability margin and to correlate flight test mode shapes with those computed from finite element analyses. By tracking trends during flight test, this tool can help to predict the onset of large amplitude oscillation that occur during flight (e.g., Limit Cycle Oscillation). For example, tracking of the system damping meter time history during maneuvers can establish thresholds when recorded amplitudes of oscillation exceed pre-determined terminate values. These thresholds can then be used as a predictor gauge during follow-on maneuvers. The mode shape correlation display, in conjunction with the aircraft aeroelastic response displayed in the ZAMS tool, will help identify how the structure modes interact with the aerodynamics throughout all flight conditions. In addition, this tool can be used to validate the finite element analysis model, typically done through expensive Ground Vibration Testing (GVT), by correlating the extracted flight test modes during low speed flight (i.e., where aeroelastic effects on the structure are minimal). Use of the proposed tools will help to minimize aircraft fatigue thereby reducing maintenance costs as well as provide valuable insight into the aero-structure interaction phenomenon that can lead to reduced flight testing. Mode shape correlation can alleviate costs and burden associated with GVT. Users of these tools will include IADS customers, such as, Edwards AFB, Eglin AFB, Naval Air Weapons Center, Korean Aerospace, Pratt & Whitney, Israeli Air Force, Singapore Air Force, Cessna, Bell Helicopter, Northrop Grumman, Alenia/Italy, General Atomics, Boeing, Gulfstream, Holloman AFB, Raytheon, Hill AFB, and Lockheed.
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 124.54K | Year: 2014
The overall objective of this Phase I project is to develop a nonlinear trim module in FUN3D for enabling the determined and over-determined trim analyses to be performed by FUN3D with static aeroelastic effects. Based on an optimization formulation, the over-determined trim analysis can determine the optimum control surface scheduling of multiple control surfaces to achieve the best aerodynamic efficiency of the aircraft using the high-fidelity Navier-Stokes (N-S) solver in FUN3D. At the critical loads flight conditions, the optimum control surface scheduling can minimize the design loads; leading to a lighter and more flexible structural design. At the cruise conditions, the optimum control surface scheduling can aeroelastically deform the more flexible structure to an optimum shape for induced drag minimization at cruise. One non-conventional design concept under investigation by NASA is the Variable Camber Continuous Trailing Edge Flap (VCCTEF) system that utilizes multiple advanced actuators such as shape memory alloys (SMA) to achieve an optimum continuous deformed wing shape for obtaining the best aerodynamic efficiency. The VCCTEF design concept for the aerodynamic efficiency improvement will be ultimately verified by wind tunnel testing. However, such a wind tunnel testing will be impractically without a viable wind tunnel test plan that can provide a guideline for seeking the optimum actuation scheduling in the multi-dimensional design space. This viable wind tunnel test plan for testing the VCCTEF concept can be established by the FUN3D nonlinear trim module.
Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase II | Award Amount: 749.79K | Year: 2015
ABSTRACT:Both commercial and military aircraft are being flown/utilized for extended operational time; a more accurate prediction of residual life and the inspection interval for an individual aircraft is required, as these aging aircraft are kept in operational status. A technique for converting actual aircraft measured flight usage data into accurate calculated stresses/strains on the structural "hot spots" via physics-based, real-time aeroservoelastic simulations will be extremely useful to the Air Force to continue the operational readiness of its aging fleet. In Phase I, ZONA Technology, Inc. successfully demonstrated distributed loads calculations using the Stick-to-Stress Dynamic Flight Simulation (StS-DFS) framework and F-15 Saudi (F-15SA) flight test data, taking into account changing fuel mass. The overall objective of the Phase II effort is to establish a broad simulation capability for loads generation using StS-DFS, including store mass variation. We will use the F-15SA as a demonstration case to validate StS-DFS predicted loads with flight test data, account for variation of mass and pilot from aircraft to aircraft, generate stress time history due to various maneuvers, and perform fatigue analysis for estimation of residual fatigue life. The outcome of this effort shall be a crucial step towards the Airframe Digital Twin vision, leading to an updated life prediction and inspection interval of individual aircraft.BENEFIT:The technology developed during this Phase II effort will result in a technique for converting actual aircraft measured flight usage data into accurate calculated stresses/strains on the structural hot spots via physics-based, real-time aeroservoelastic simulations; this resultant technology is called the StS-DFS Framework. The StS-DFS Framework will have the capability to simulate the key aeroelastic coupling mechanism between structural dynamics and nonlinear unsteady aerodynamics with classical rigid body dynamics to generate a broad range of loads including the store ejection loads, maneuver loads, gust loads, buffet loads with the consideration of the effect of uncertainty associated with aircraft-to-aircraft variability, leading to an estimation of residual fatigue life of the airframe. This capability is a crucial early step towards the Airframe Digital Twin vision. The StS-DFS Framework will promote physical understanding of observed in-flight dynamic behavior by virtual flight test simulations. Since the StS-DFS Framework is able to accurately predict the fatigue life and damage of individual aircraft, it will be highly desirable to both military and commercial aircraft companies. The target customers for the StS-DFS Framework include all aircraft manufacturers, owners, and maintenance organizations, most of which are current ZONA customers. Potential customers include Edwards AFB, Eglin AFB, AFRL, NASA, NAVAIR/NAWC/Navy, US Army, Lockheed Martin, Boeing, Northrop-Grumman, Raytheon, General Atomics Aeronautical Systems, Cessna Aircraft, Pilatus, Airbus, and others.
Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase I | Award Amount: 149.94K | Year: 2014
ABSTRACT: Both commercial and military aircraft are being flown/utilized for extended operational time. The aircraft cumulative flight hours often times extends the original design limits. Each different aircraft manufacturer calculates aircraft fatigue and damage using different techniques. A more accurate prediction of remaining life and inspection interval for an individual aircraft is required, as these aging aircraft are kept in operational status. ZONA Technology, Inc. has been working closely with The Boeing Company to develop a software process to more accurately predict the maneuver loads on an aircraft. This program is called"Stick-to-Stress Dynamic Flight Simulation"(StS-DFS) that can generate structural component loads and stresses due to a pilot stick input command. In the Phase I effort, we will further enhance StS-DFS to adopt previously recorded flight data as input and account for the mass variations due to fuel burn and mission-dependent stores to reflect the impact due to variations in pilot, payloads and fuel burn on the loads of the aircraft. The F-15 Saudi aircraft, an on-going Boeing's project for verifying an new"fly-by-wire"capability, will be selected to validate the enhanced StS-DFS with the newly acquired flight test data from the F-15 Saudi flight test. BENEFIT: Recently, the Air Force Research Laboratory has produced a long-term vision, called the Airframe Digital Twin that calls for the development of a physics based process of determining initial or remaining aircraft structural life. The outcome of the proposed Phase I effort will be one of the crucial early steps towards the Airframe Digital Twin vision. Several U.S. military aircraft such as F-16, F-15, C-5 and A-10 and commercial aircraft are reaching or are already beyond their originally designed fatigue lives. To identify their residual fatigue life or extend their fatigue life by retrofit, accurate loads spectra to perform fatigue analysis or ground fatigue tests on these aircraft is required. Such an accurate loads spectra can be generated by StS-DFS using the recorded flight test data of individual fleet members of these aircraft as input to keep track of the individual fatigue life as proposed in the USAF Digital Twin vision with the concept of improved fatigue calculation. In Phase II, the ZONA/Boeing team will develop a process that can extract the stresses generated by StS-DFS around the identified fatigue critical regions in the structure and use these stresses as input to their respective structural component damage tolerance models; leading to an updated life prediction and inspection interval of an individual aircraft.