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A Guide to APU Health Management

AIR5317 establishes the foundation for developing a successful APU health management capability for any commercial or military operator, flying fixed wing aircraft or rotorcraft. This AIR provides guidance for demonstrating business value through improved dispatch reliability, fewer service interruptions, and lower maintenance costs and for satisfying Extended Operations (ETOPS) availability and compliance requirements.

Aerospace & Defense Technology: September 2023

How Thunderbolt 4 Helps Bring Fault-Tolerant, Distributed Systems to Market Delivering Operational Energy to Enhance Warfighter Capability Optoelectronic Analog Signal Transmission Takes Center Stage Amidst Aerospace and Defense Innovation Shaking Outside the Box to Advance Flight Research An Introduction to Quantum Computing How Laser Communications Innovation is Finally Coming of Age and Driving Innovation in Defense Spatial Calibration for Accurate Long Distance Measurement Using Infrared Cameras A new spatial calibration procedure has been introduced for infrared optical systems developed for cases where camera systems are required to be focused at distances beyond 100 meters. Towards Greater Sensitivity: A Brief FTIR and Infrared-Based Cavity Ring Down Spectroscopy Comparative Study A presentation of work comparing efficacy of a traditional IR method used as a standard within the U.S.
Journal Article

Experimentally Validated Neural Networks for Sensors Redundancy Purposes in Spark Ignition Engines

The MAP and MAF are predicted through two virtual sensors based on two independent FNNs, having the same inputs, constituted by the engine speed and the throttle angle. An experimental investigation based on an aircraft endurance test of two hours proposed by the European Aviation Safety Agency (EASA) has been made on a controlled and monitored CMD 22 engine for comparing the experimentally measured MAP and MAF with the predicted ones by the FNNs.

Aerospace & Defense Technology: August 2023

Electrifying Aviation: The Path to Decarbonizing the Skies /Electric aviation mirrors the early stages of the electric vehicle revolution Advances in Military Avionics Technologies Create New Challenges for RF Test and Measurement Plasma Electrolytic Oxidation: The Future of Lightweight Designs in Aerospace and Defense Advanced RF Simulation Reduces Cost and Schedule Risk Assure 5G NTN Performance Before Launch In the complex and quickly evolving 5G NTN landscape, simulating, emulating, and evaluating RF systems boosts mission success. Qualification of Multi-Channel Direction Finding Radar Receivers in The Lab Bullet Impact Testing of Ammunition and Explosives at Picatinny Arsenal A bullet impact (BI) test for evaluating the response of energetically loaded items has been established at the U.S. Army Combat Capabilities Command (DEVCOM) Armaments Center (AC) Explosive Development Facility.

Metallic Materials Properties Development and Standardization (MMPDS) Handbook - 2023

The Metallic Materials Properties Development and Standardization MMPDS-2023 supersedes MMPDS-17 and prior editions of the MMPDS Handbook as well as all editions of MIL-HDBK-5, Metallic Materials and Elements for Aerospace Vehicle Structures Handbook that was maintained by the U.S. Air Force. The last edition, MIL-HDBK-5J was cancelled by the U.S. Air Force in March 2006. This document contains design information on the mechanical and physical properties of metallic materials and joints commonly used in aircraft and aerospace vehicle structures. All information contained in this Handbook has been reviewed and approved using a standardized process. The development and ongoing maintenance process involves certifying agencies, including the FAA, DoD, and NASA, and major material suppliers and material users worldwide. The information and procedures in this Handbook are continuously reviewed and modified or removed as determined to be appropriate.
Technical Paper

UAV Icing: Numerical Simulation of Icing Effects on Wing and Empennage

Therefore, the 2D profiles of these airfoils, which are RG-15 for the wing and SD8020 for rudder and elevator, are investigated. The investigated angles of attack are between –5° and 14° in 0.5° increments. ...This work investigates numerically icing effects on wing and empennage over a wide range of icing parameters. This is conducted using the icing CFD code FENSAP-ICE on the Maritime Robotics PX-31 Falk UAV.
Technical Paper

The Effect of Large Droplet and Spanwise Ridge Ice Accretion on the Aerodynamic Performance of Swept Wings

Ridge size and location had significant effects on the performance and the lower-surface ridge was important contributing to the drag at low angle of attack and lift at high angle of attack due to the movement of the attachment line around the leading edge. ...Wind tunnel tests were performed on an 8.9-percent scale semispan wing in the Wichita State University 7x10-foot wind tunnel with simulated ice accretion shapes. ...Three Reynolds number and Mach number combinations were tested over a range of angles of attack. Aerodynamic forces and moments were acquired from the tunnel balance and surface pressures and oil flow visualizations were acquired.
Technical Paper

UAV Icing: 3D Simulations of Propeller Icing Effects and Anti-Icing Heat Loads

In-flight atmospheric icing is a significant threat to the use of unmanned aerial vehicles (UAVs) in adverse weather. The propeller of the UAV is especially sensitive to icing conditions, as it accumulates ice at a faster rate than the wings of the UAVs. Ice protection systems can be developed to counteract the danger of icing on the propeller of UAVs. In this study, the influence of different meteorological conditions on a propeller of a UAV is analyzed for a UAV with a wingspan of a few meters. The ice accretion and the performance degradation and the required anti-icing heat fluxes have been calculated using numerical methods with ANSYS FENSAP-ICE. This analysis has been used to evaluate the critical conditions for the operation of a UAV in icing conditions and the design of a thermal IPS system for a propeller. The highest ice mass has been found at a temperature of −10 °C and an MVD of 20 μm in intermittent maximum icing conditions.
Technical Paper

IMPACT: Numerical Study of Aerodynamics of an Iced Forward-Swept Tail with Leading Edge Extension

The aerodynamic analyses of the iced tails were carried out using Ansys Fluent Aero with angle of attacks from 0° to -15°. All three sweeps show reduction in lifting performance under icing conditions, due to early separation. ...This paper describes a CFD-based investigation of the effects of sweep on the aerodynamic performance of a novel forward-swept horizontal stabilizer concept in icing conditions. ...The concept features an unconventional forward sweep, combined with a high lift leading edge extension (LEX) located within a fuselage induced droplet shadow zone, providing passive protection from icing.
Technical Paper

Development and Demonstration of a Low Power Electrothermal Wing Ice Protection System for Regional Aircraft

Under the EU Clean Sky 2 research project InSPIRe – Innovative Systems to Prevent Ice on Regional Aircraft, numerical and experimental studies have been performed to investigate the potential to minimise the electrical power required for wing ice protection on a regional aircraft wing. In a standard electrothermal de-ice protection scheme there is a parting strip heater which runs along the full spanwise protected extent and is permanently powered.
Technical Paper

Additional Comparison of Ice Shapes on Full-Chord and Truncated Swept Wing Models from January 2022

A hybrid design is where the full-scale leading edge of a wing section is maintained only to a certain percentage of the local chord, while the aft section of the model is redesigned into a shortened or truncated planform. ...An initial study was conducted in 2020 where the ice shape geometries on a full-chord length version of the swept CRM65 wing model were compared to those from the hybrid version of CRM65 that were obtained in the NASA Icing Research Tunnel in 2015. ...A follow-on test was conducted in 2022 and obtained ice shapes on both full-chord and hybrid wing models during the same test campaign to eliminate the differences in the tunnel spray nozzle configuration and calibration as a cause for the differences observed during the previous investigation.
Technical Paper

Experimental Investigation of a CRM65 Wingtip Mockup under Appendix C and Appendix O Icing Conditions

Research institutes and companies are currently working on 3D numerical icing tools for the prediction of ice shapes on an international level. Due to the highly complex flow situation, the prediction of ice shapes on three-dimensional surfaces represents a challenge. An essential component for the development and subsequent validation of 3D ice accretion codes are detailed experimental data from ice shapes accreted on relevant geometries, like wings of a passenger aircraft for example. As part of the Republic of Austria funded research project JOICE, a mockup of a wingtip, based on the National Aeronautics and Space Administration common research model CRM65 was designed and manufactured. For further detailed investigation of electro-thermal de-icing systems, various heaters and thermocouples were included.
Technical Paper

Advancements in CHAMPS for Multi-Layer Ice Accretion on Aircraft

The method called Impact Angle Correction (IAC) method in the literature is implemented and consists in setting in an additional loop the components solved on the surface, namely the thermodynamic exchanges and the geometry update, to consider the change in the surface normal vectors. ...This local roughness could allow to better capture the ice horn locations, angle and height. Two-dimensional results presented in this work show in particular that lower horns are better captured when using a local roughness model.
Technical Paper

Icing Simulation Results Using Lagrangian Particle Tracking in Ansys Fluent Icing

This paper introduces the Lagrangian particle tracking technology readily available in Ansys Fluent in the in-flight icing simulation workflow, which normally uses the Eulerian approach for droplet flows. The Lagrangian solver is incorporated in the Fluent Icing workspace which is to become the next-gen in-flight icing simulation tool provided by Ansys. Lagrangian tracking will eventually be used for SLD and ice crystal rebound and re-impingement calculations in the Ansys workflow. Here we introduce some preliminary results with the current state of its implementation as of Fluent Icing release 2023R2. Example cases include several selections from the 1st Ice prediction workshop with experimental comparisons as well as results obtained earlier with the Eulerian droplet solution strategy. Collection efficiency comparisons on clean geometries show good agreement between Eulerian and Lagrangian methods when the particle seeds are in the millions range.
Technical Paper

Computational Icing Analysis on NASA’s SIDRM Geometry to Investigate Collection Efficiency

All three icing codes underpredicted the final ice shape using a single-shot constant ice density approach, with more difficulty coming from the strut leading edge ice shape due to the swept wing like flow field. NASA’s overall goal for this effort is to develop computational icing tools to assist in the design and certification of engines for flight in icing conditions.