Browse Topic: Wings

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NOISE ANALYSIS IN DIFFERENT FLAPPING MECHANISMS FOR EFFICIENT FLYING2025-01-002105/05/2023
In a variety of intricate and dynamic settings, flying animals, like birds and insects [5],[8], can fly with efficiency. Despite being stated as "unsteady aerodynamics", the flapping of birds was the first biological mechanism that inspired humans to fly. Though flapping wings is the most efficient way of flying, the main hindrance is its unsteady nature of gaining a counter-lift for each flap. Compared to current manned aerial vehicles, flying animals fly at a lower Reynolds number. A fluid's ratio of viscous to inertial forces is represented by the Reynolds number, which is a dimensionless quantity. The ratio of forward speed to flapping frequency is represented by the dimensionless number known as the decreased frequency. Yet, by utilizing these beneficial animal flying traits, unmanned aerial vehicles (UAVs) functioning in the low Reynolds number zone can be enhanced. The primary aim of this project is to analyze two flapping mechanisms: straight continuous wing and swept & bent
Keshav Kumar, A B, Patric, Alan, R, Asad Ahmed, Srinivasan, Venkatramanan, Mani, Midhun, Jayachandran, Rohith
Investigation of the effectiveness of plasma actuators at various chord positions of an airfoil for flow separation control2022-26-113505/26/2022
This paper's principal aim is to investigate the effect of a plasma actuator on the airflow over an airfoil. Dielectric Barrier Discharge (DBD) Plasma actuators are lauded as one of the most efficient active control devices in the field of aerodynamics. It owes this to ionizing and consequently exerting body force on the air without increasing the structural complexity of the airfoil. However, it is imperative to know the characteristics of plasma positioning at a specific angle of attack to ensure optimum usage. NACA 0012 airfoil was used in the simulations to demonstrate the proficiency of multiple plasma actuators to delay flow separation at increasing angles of attack at various chord positions by using a steady-state RANS model solver on a two-dimensional geometry at subsonic speeds corresponding to a Reynolds Number of the order of 10^5. ANSYS Fluent solver was used to examine the significant increase in the numerically obtained Lift-to-Drag ratio, and the aerodynamic
Aryan, Suryansh, Ahmed, M Muzheir, Acharya, Sagar, Dubey, Sukanya
Bird strike analysis on nanocomposite materials for aerospace applications2022-26-114505/26/2022
Over the years, bird strike has become a serious threat as it is inevitable and can be catastrophic. Several accidents occur due to the bird collision with wing leading edges, causing serious structural damage that may be permanent. Therefore, the failure induced by birds on the leading edge has persuaded much research interest. To heighten the impact resistance during bird strike with the leading edge of the wing, nanocomposite materials are proposed as it has improved characteristics like high surface-to-volume ratio, enhanced mechanical properties like high ductility, fracture toughness with no decrease of strength in structure. In order to achieve material constants of the nanocomposites, the finite-element method (FEM) and representative volume element (RVE) which is a micromechanical analysis approach will be considered. A comparative study will be done on different volume fractions of nanofillers impregnated with the composite material to find the optimum material properties
Neigapula, Keerthana, Anand, Sumit, Devi, Monisha, Tiwari, Anawil, Kumar, Siddharth
A comparative study between Flax-Fiber Reinforced Polymer and Balsa wood for Aero-structure applications. 2022-26-119905/26/2022
When air flows over a wing, a pressure difference is generated between the upper and lower camber of the wing. This pressure difference is responsible for lift generation. Since the wing is the primary lifting surface of all aircraft, the structure itself must be capable of handling all the loads imposed upon it. This study aims to perform a trade-off between Balsa wood and a natural fiber composite namely Flax Fiber Reinforced Polymer and evaluating their performance using ANSYS. Balsa wood is the most common material used for building homebuilt remote-controlled aircraft. This makes the aircraft light but restricts its performance as it cannot handle cyclic loads over a period of the cycle. Thus, a natural fiber composite is being chosen as a substitute for the conventional Balsa wood. The wing is modeled using SOLIDWORKS 2018 and includes 5 ribs and a rectangular spar at the maximum thickness/chord %. The composite material is built using ANSYS ACP wherein all the laminates and
Phatarphod, Soham, Swain, Prasant Kumar, Sharma, Narayan, Maiti PhD, Dipak Kumar
Study on the Influence of Mass Flow Rate over a National Advisory Committee for Aeronautics 6321 Airfoil Using Improved Blowing and Suction System for Effective Boundary Layer Control01-14-02-001108/06/2021
The numerical analysis of the three-dimensional (3D) flow over a National Advisory Committee for Aeronautics (NACA) 6321 airfoil to evaluate the mass flow rate by using a novel method Improved Blowing and Suction System (IBSS) to control the boundary layer is presented in this study. Analysis is performed based on 3D Reynolds-Averaged Navier-Stokes (RANS) equation with a K-omega SST solver. The aerodynamic performance of the NACA 6321 is analyzed at a Mach number of 0.10 with three different mass flow rates, namely, 0.08 kg/s, 0.10 kg/s, and 0.12 kg/s. From the study, it is seen that when the mass flow rate decreased, the aerodynamics performance also reduced, and the aerodynamic performance improved with the increase in mass flow rate. Results also show that a mass flow rate of 0.10 kg/s improved the stalling angle of attack (AoA) by 60% and coefficient of lift (CL) by 50%, enabling optimum efficiency of the aircraft wing in all aspects compared to the baseline airfoil model. The mass
Karuppiah, Balaji, Wessley, Jims John
Rear Fuselage PackerTBMG-3759909/01/2020
Kaman UK Darwen, UK +44 1254 706000
Device “Hears” Disease Through Structures Housing CellsTBMG-3747708/01/2020
Similar to how a picked lock indicates someone has broken into a building, the stiffening of a structure surrounding cells in the human body can indicate that cancer is invading other tissue. Monitoring changes to this structure, called the extracellular matrix, would give researchers another way to study the progression of disease. But detecting changes to the extracellular matrix is hard to do without damaging it.
Simulation of Transient On-Road Conditions in a Closed Test Section Wind Tunnel Using a Wing System with Active Flaps2020-01-068804/14/2020
Typical automotive research in wind tunnels is conducted under idealized, stationary, low turbulence flow conditions. This does not necessarily reflect the actual situation in traffic. Thus, there is a considerable interest to simulate the actual flow conditions. Because of this, a system for the simulation of the turbulence intensity I, the integral linear scale L and the transient angle of incidence β measured in full-scale tests in the inflow of a test vehicle was developed and installed in a closed-loop, closed test section wind tunnel. The system consists of four airfoils with movable flaps and is installed in the beginning of the test section. Time-series of the flow velocity vector are measured in the empty test section to analyze the system’s envelope in terms of the turbulence intensity and the integral length scales. It is shown that the length scales in spanwise and in driving (streamwise) direction can be varied from 0.15 m to 7.9 m and from 0.15 m to 2.5 m, respectively
Wilhelmi, Henning, Jessing, Christoph, Bell, James, Heine, Daniela, Wagner, Andreas, Wiedemann, Jochen, Wagner, Claus
CAD-Based Optimization of a Race Car Front Wing2020-01-062404/14/2020
The aerodynamics of the front wing of modern race cars are critical to the performance of the vehicle. The Formula 1 line up represents the state of the art in this field as there are some very complex aerodynamic designs on display. It is strange, however, that there is no agreement on twist direction for the multiple wing sections of the front wing. This paper addresses this question by posing it as an optimization problem. The geometry of the wings has been simplified so that the twist of the upper sections could be studied in isolation. The whole assembly consisted of only two high lift surfaces. The forward wing remained fixed for the study, and twist of the secondary wing became the primary focus. Its geometry was generated by lofting a set of cross-sections at specified angles to create the surface. The resulting geometry was automatically meshed and then evaluated using CFD. This fully automated process was then used to find an ideal twist distribution of the secondary wing
Tolchinsky, Ilya, Carrigan, Travis, Dawson, Joshua
Application of Extended Messinger Models to Complex Geometries2020-01-002203/10/2020
Since, ice accretion can significantly degrade the performance and the stability of an airborne vehicle, it is imperative to be able to model it accurately. While ice accretion studies have been performed on airplane wings and helicopter blades in abundance, there are few that attempt to model the process on more complex geometries such as fuselages. This paper proposes a methodology that extends an existing in-house Extended Messinger solver to complex geometries by introducing the capability to work with unstructured grids and carry out spatial surface streamwise marching. For the work presented here commercial solvers such as STAR-CCM+ and ANSYS Fluent are used for the flow field and droplet dispersed phase computations. The ice accretion is carried out using an in-house icing solver called GT-ICE. The predictions by GT-ICE are compared to available experimental data, or to predictions by other solvers such as LEWICE and STAR-CCM+. Three different cases with varying levels of
Gupta, Avani, Sankar, Lakshmi, Kreeger, Richard
Multi-Objective Flight Control Optimization FrameworkTBMG-3620103/01/2020
Composite materials are used in aerospace design because of their high strength-to-weight ratio. On modern airplanes, composite wings offer a greater degree of aerodynamic efficiency due to weight savings but at the same time introduce more structural flexibility than their aluminum counterparts. Under off-design flight conditions, changes in the wing shape due to structural flexibility cause the wing aerodynamics to be non-optimal. This effect could offset any weight-saving benefits realized by the composite wings. Structural flexibility could also cause adverse interactions with flight control and structural vibration that can compromise aircraft stability, pilot handling qualities, and passenger ride quality.
High-Performance, Piezoelectric, Hybrid Synthetic Jet ActuatorsTBMG-3618103/01/2020
NASA Langley Research Center has invented three serial high-performance, piezoelectric, hybrid synthetic jet actuators to provide active flow control for current and future wing-borne vehicles in subsonic, transonic, and supersonic flow. Effective active flow control results in reduced vehicle drag and the prevention of events that can lead to catastrophic loss.
Stall Mitigation and Lift Enhancement of NACA 0012 with Triangle-Shaped Surface Protrusion at a Reynolds Number of 105 01-12-02-000711/21/2019
Abstract Transient numerical simulations are conducted over a NACA 0012 airfoil with triangular protrusions at a Reynolds number (Re) of 100000 using the γ-Reθ transition Shear Stress Transport (SST) turbulence model. Protrusions of heights 0.5%c, 1%c, and 2%c are placed at one of the three locations, viz, the leading edge (LE), 5%c on the suction surface, and 5%c on the pressure surface, while the angle of attack (AOA) is varied between 0° and 20°. Results obtained from the time-averaged solution of the unsteady Navier-Stokes equation indicate that the smaller protrusion placed at 5%c on the suction surface improves the post-stall lift coefficient by up to 59%, without altering the pre-stall characteristics. The improvement in time-averaged lift coefficients comes with enhanced flow unsteadiness due to vigorous vortex shedding. For a given protrusion height, the vortex shedding frequency decreases as the AOA is increased, while the amplitude of fluctuations in lift coefficient
Bodavula, Aslesha, Yadav, Rajesh, Guven, Ugur
Structure Deformation Calculation Program for Structural Shape MonitoringTBMG-3528910/01/2019
Researchers at NASA’s Armstrong Flight Research Center are pioneering shape-sensing technologies that seek to maximize structural integrity and efficiency. A new and versatile computer program offers critical shape-monitoring capabilities and has applications for a wide variety of structures.
New Airplane Wing Assembled from Tiny Identical PiecesTBMG-3527710/01/2019
A radically new kind of airplane wing, assembled from hundreds of tiny identical pieces, can change shape to control the plane’s flight, and could provide a significant boost in aircraft production, flight, and maintenance efficiency. The new approach to wing construction could afford greater flexibility in the design and manufacturing of future aircraft.
C919 Trailing Edge Assembly Interchangeable Tooling2019-01-188009/16/2019
Traditional Trailing Edge (TE) assembly that utilise fixtures for accurate positioning of aircraft (a/c) parts do not allow for removal of specific tooling from the fixtures to travel with the TE, post assembly. Instead, the tooling that positions all the primary a/c assembly datums generally utilise precision pins of various sizes that index and clamp the a/c ribs. Often it is difficult to remove the pins post assembly before the spar can be taken out of the fixture. Use of hammers is common place to hit pins out of holes which is less than ideal considering the a/c parts can be fragile and the tooling is precision set. Also, the Main Assembly Fixture (MAJ) that will receive the TE will inevitably need to relocate some if not all the primary a/c ribs and therefore will most likely be subject to some amount of persuasion. Electroimpact have for many years used cup cone locators that allows static tooling to be temporarily ‘loosened’ and therefore made more compliant for pin insertion
Dineley, James
Advanced Assembly Solutions for the Airbus RACER Joined-Wing Configuration2019-01-188409/16/2019
The Rapid And Cost Effective Rotorcraft (RACER) is being developed by Airbus Helicopters (AH) to demonstrate a new Vertical Take-Off and Landing configuration to fill the mobility gap between conventional helicopters and aeroplanes. RACER is a compound rotorcraft featuring wings and multiple rotors. The wing arrangement suggested by AH is defined as a staggered bi-plane joined configuration with an upper and a lower straight wing, either side of the fuselage, connected at their outboard extent to form a triangular structure. The ASTRAL consortium, consisting of the University of Nottingham and GE Aviation Systems, are responsible for the design, manufacture, assembly and testing of the wings. Producing an optimised strategy to assemble a joined-wing configuration for a passenger carrying rotorcraft is challenging and novel. The objective of this work concerns all aspects of assembling the joined-wing structure. The joined-wing and fuselage structures will be produced independently and
Bainbridge, David, Bacharoudis, Konstantinos, Cini, Andrea, Turner, Alison, Popov, Atanas, Ratchev, Svetan
Landing Gear Integration into Aircraft Structure in Early Design Stage2019-01-189009/16/2019
The demanded development towards various emission reduction goals set up by several institutions forces the aerospace industry to think about new technologies and alternative aircraft configurations. With these alternative aircraft concepts, the landing gear layout is also affected. Turbofan engines with very high bypass ratios could increase the diameter of the nacelles extensively. In this case, mounting the engines above the wing could be a possible arrangement to avoid an exceedingly long landing gear. Thus, the landing gear could be shortened and eventually mounted at the fuselage instead of the wings. Other technologies such as high aspect ratio wings have an influence on the landing gear integration as well. To assess the difference, especially in weight, between the conventional landing gear configuration and alternative layouts a method is developed based on preliminary structural designs of the different aircraft components, namely landing gear, wing and fuselage. Simplified
Kling, Ulrich, Hornung, Mirko
Preliminary Design of Hydraulic and Pneumatic System Architectures for a Morphing Flight Control Structure2019-01-191609/16/2019
Bionics in aeronautics has the potential to increase the performance and efficiency of aircraft significantly. Inspired by the wings of birds, morphing wing structures have been extensively investigated over the last decades. The continuous adaption of the wings over a large scale of the flight envelope enables an optimization of the aerodynamic characteristics and, this way, a reduction of the fuel consumption. Additionally, those structures could support or replace traditional flight control surfaces. Depending on the morphing technology, different systems may be suitable to actuate the morphing structure. An early inclusion of the system architecture into the development of the morphing technology enables designing an optimal system in compliance with all requirements. Therefore, this paper discusses the conceptual design of system architectures for a novel morphing wing structure that is used for flight control. The benefits of morphing structures for aircraft applications are
Schäfer, Michael, Schäfer, Andreas, Bertram, Oliver
Low Cost Reconfigurable Jig Tooling and In-Process Metrology for High Accuracy Prototype Rotorcraft Wing Assembly2019-01-187709/16/2019
Reconfigurable tooling frames consisting of steel box sections and bolted friction clamps offer an opportunity to replace traditional expensive welded steel tooling. This well publicized reconfigurable reusable jig tooling has been investigated for use in the assembly of a prototype compound helicopter wing. Due to the aircraft configuration, the wing design is pinned at both ends and therefore requires a higher degree of end to end accuracy, over the 4m length, than conventional wings. During the investigation some fundamental issues are approached, including: Potential cost savings and variables which effect the business case. Achievable Jig accuracy. Potential sources of instability that may affect accuracy over time. Repeatability of measurements with various features and methods. Typical jig stability over 24hrs including effects of small temperature fluctuations. Deflections that occur due to loading. The cost benefit of reusable tooling in a low volume prototype scenario is
Crossley, Richard J., Ratchev, Svetan
3D Optical ScannerTBMG-3511609/01/2019
NVision, Inc. Southlake, TX 817-416-8006
Additional Comparison of Iced Aerodynamic Measurements on a Swept Wing from Two Wind Tunnels2019-01-198606/10/2019
Artificial ice shapes of various geometric fidelity were tested on a wing model based on the Common Research Model. Low Reynolds number tests were conducted at Wichita State University’s Walter H. Beech Memorial Wind Tunnel utilizing an 8.9% scale model, and high Reynolds number tests were conducted at ONERA’s F1 wind tunnel utilizing a 13.3% scale model. Several identical geometrically-scaled ice shapes were tested at both facilities, and the results were compared at overlapping Reynolds and Mach numbers. This was to ensure that the results and trends observed at low Reynolds number could be applied and continued to high, near-flight Reynolds number. The data from Wichita State University and ONERA F1 agreed well at matched Reynolds and Mach numbers. The lift and pitching moment curves agreed very well for most configurations. This confirmed results from previous tests with other ice shapes that indicated the data from the low Reynolds number tests could be used to understand iced
Lee, Sam, Broeren, Andy, Woodard, Brian, Lum, Christopher, Smith, Timothy
Aerodynamic Comparison of Freezing Rain and Freezing Drizzle Conditions at the RTA Icing Wind Tunnel2019-01-202306/10/2019
The simulation of icing conditions in icing wind tunnels (IWTs) is a significant element in the certification of aircraft components and offers unique possibilities for research purposes. Up to 2014 only the conditions defined in Appendix C of the EASA Certification Specification 25, respectively the FAA Code of Federal Regulations Title 14 Part 25 were used for the certification processes in IWTs. In addition, Appendix O was introduced in 2014 to cover the supercooled large droplet (SLD) icing conditions of freezing drizzle and freezing rain, which pose a potential risk for flight safety. The simulation of SLD icing in IWTs is, due to the different behavior of the large droplets, very challenging and not all required conditions have successfully been recreated yet. RTA Rail Tec Arsenal Fahrzeugversuchsanlage GmbH has focused on the simulation of in-flight icing conditions since 2012 and increased effort was put in the simulation of SLDs in recent years. During several research
Breitfuß, Wolfgang, Wannemacher, Michael, Knöbl, Florian, Ferschitz, Hermann
Influence of Freestream Temperature on Ice Accretion Roughness2019-01-199306/10/2019
The influence of freestream static temperature on roughness temporal evolution and spatial variation was investigated in the Icing Research Tunnel (IRT) at NASA Glenn Research Center. A 53.34 cm (21-in.) NACA 0012 airfoil model and a 152.4 cm (60-in.) HAARP-II business jet airfoil model were exposed to Appendix C clouds for fixed exposure times and thus fixed ice accumulation parameter. For the base conditions, the static temperature was varied to produce different stagnation point freezing fractions. The resulting ice shapes were then scanned using a ROMER Absolute Arm system and analyzed using the self-organizing map approach of McClain and Kreeger. The ice accretion prediction program LEWICE was further used to aid in interrogations of the ice accretion point clouds by using the predicted surface variations of local collection efficiency. The resulting equivalent sand-grain roughness heights predicted using the correlation of Flack and Schultz are compared to the roughness
McClain, Stephen T., Vargas, Mario, Tsao, Jen-Ching, Broeren, Andy
Frostwing Co-Operation in Aircraft Icing Research2019-01-197306/10/2019
The aerodynamic effects of Cold Soaked Fuel Frost have become increasingly significant as airworthiness authorities have been asked to allow it during aircraft take-off. The Federal Aviation Administration and the Finnish Transport Safety Agency signed a Research Agreement in aircraft icing research in 2015 and started a research co-operation in frost formation studies, computational fluid dynamics for ground de/anti-icing fluids, and de/anti-icing fluids aerodynamic characteristics. The main effort has been so far on the formation and aerodynamic effects of CSFF. To investigate the effects, a generic high-lift common research wind tunnel model and DLR-F15 airfoil, representing the wing of a modern jet aircraft, was built including a wing tank cooling system. Real frost was generated on the wing in a wind tunnel test section and the frost thickness was measured with an Elcometer gauge. Frost surface geometry was measured with laser scanning and photogrammetry. The aerodynamic effect of
Koivisto, Pekka, Soinne, Erkki, Broeren, Andy, Bond, Thomas
Separating-Reattaching Flows Over an Iced Airfoil2019-01-194606/10/2019
Delayed Detached Eddy Simulations (DDES) of separating-reattaching flows on the suction side of an ice-contaminated airfoil were conducted. A single-section straight-wing NACA23012 airfoil with leading-edge ice was studied. The geometry represents a realistic glaze horn-ice contamination obtained during the icing test campaigns described in [1], which has aerodynamic data for comparison. The three-dimensional transient flow behavior was simulated using the open-source flow solver OVERFLOW, version 2.2l [2] developed by NASA Langley Research Center. Configurations at three angles of attack that exhibit unsteady flow behavior starting with the bursting angle were examined at Mach number of 0.18 and Reynolds number of 1.8x106. As the stall angle was approached the aerodynamic performance parameters displayed large-scale unsteadiness where periods of attached and separated flows were observed. The time-averaged results show good agreement with the aerodynamic test data. The calculated
Oztekin, Ezgi, Riley, James
On-Ground Cold Soak Fuel Frost Modeling2019-01-197506/10/2019
In this paper a cold soak fuel frost modeling for an aircraft wing tank is presented. Numerical prediction is compared with experimental data and a qualitative verification for the frost formation and melting is also shown. The numerical simulation showed good agreement with experimental observations. The model was used to define, through a Monte Carlo analysis, two different frost formations whose impact on aircraft handling was evaluated by flight tests using representative grits.
Silva, Daniel Martins da, Santos, Luis, Katchborian, André, Sousa, Rodrigo
Equivalent Sand Grain Roughness Correlation for Aircraft Ice Shape Predictions2019-01-197806/10/2019
Many uncertainties in an in-flight ice shape prediction are related to convection heat transfer coefficient, which in turn depends on the flow, turbulence and laminar/turbulent transition models. The height of ice roughness element used to calculate the Equivalent Sand Grain Roughness height (ESGR) is a very important input of the turbulence model as it strongly influences the shape of the accreted ice. Unfortunately, for in-flight icing, the ESGR is unknown and generally calculated using semi-empirical models or empirical correlations based on a particular ice shape prediction code. Each ice shape prediction code is unique due to the models and correlations used and the numerical implementation. Ice roughness correlations do not have the same effect in each ice shape prediction code. A new approach to calculate the ESGR correlation taking into consideration the particularities of the ice shape prediction code is developed, calibrated and validated. This new approach derives a
Fortin, Guy
Simulations of Thin Film Dynamics on a Flat Plate and an Airfoil2019-01-193806/10/2019
The goal of the present study is to investigate the dynamics of a thin water film on a flat plate and an airfoil using direct numerical simulation (DNS). The first case for a wetted flat plate is used to model former experiments and investigate the dynamics of a wind-driven water film. The second case for a thin film on a NACA 0012 airfoil of chord length 0.5 m is used to investigate the dynamics of a wind-driven water film on a curved surface. Particular attention is paid to the interaction between the liquid film and the air shear-layer above the film. As the incoming airflow moves over the thin water film, instability is triggered at the gas-liquid interface. Interfacial waves develop and are advected downstream. The interaction between the air flow and the interfacial waves induces shedding vortices near the interface, which in turn perturb the liquid film farther downstream. Simulations are performed using the open source multiphase flow solvers, Gerris and Basilisk. Both solvers
Sakakeeny, Jordan, McClain, Stephen T., Ling, Yue
Lattice Boltzmann Simulations of Flow Over an Iced Airfoil2019-01-194506/10/2019
This paper presents an aerodynamic degradation study of an iced airfoil, using the Lattice Boltzmann approach with the commercial software PowerFLOW. Three-dimensional numerical simulations were performed with an extruded constant section of the GLC-305 airfoil with a leading-edge double-horn ice shape using periodic boundary conditions. The freestream Reynolds number, based on the chord, is 3.5 million and the Mach number is 0.12. An extensive comparison of the main flow features with experimental data is performed, including aerodynamic coefficients, pressure coefficient distributions, velocity and turbulence contours along with its profiles at several positions, and stagnation streamlines. The drag coefficient agrees well with experiments, in spite of a small shift. Two different wind tunnel measurements, using different measurement techniques, were compared to the CFD results, which mostly stayed in between the experimental data. Velocity and turbulence intensity contours as well
Ihi, Rafael, Ribeiro, Andre, Santos, Luis, Silva, Daniel
Computational Simulation of an Electrically Heated Ice Protection System for Composite Leading Edges of Aircraft2019-01-204106/10/2019
The performance of an electrically heated aircraft ice protection system for a composite leading edge was evaluated. The composite leading edge of the model is equipped with a Ni alloy resistance heater. A state-of-the-art icing code, FENSAP-ICE, was used for the analysis of the electrothermal de-icing system. Computational results, including detailed information of conjugate heat transfer, were validated with experimental data. The computational model was then applied to the composite leading edge wing section at various metrological conditions selected from FAR Part 25 Appendix C.
Lawrence Raj, Prince Raj, Jeong, Hojin, Roy, Rene, Kweon, Jin-Hwe, Myong, Rho Shin
Experimental and Computer Model Results for a Carbon Nanotubes Electrothermal De-Icing System2019-01-200506/10/2019
Results from a three-dimensional computer model of a Carbon Nanotubes (CNT) based de-icing system are compared to experimental data obtained at COLLINS-Ohio Icing Wind Tunnel (IWT). The experiments were performed using a prototype of a CNT based de-icing system installed in a section of a business jet horizontal tail. The 3D numerical analysis tools used in the comparisons are AIPAC [1] and CFD++. The former was derived from HASPAC, an anti-icing computer model developed at Wichita State University in 2010 [3, 9, 10]. AIPAC uses the finite volumes method for the solution of the icing problem on an airfoil leading edge (or other 3D surfaces) and relies on any CFD solver to obtain the external flow properties used as boundary conditions. AIPAC is capable of predicting 3D multi-step ice shapes under rime, glaze and mixed regimes, and can also deal with the complex dynamics of cyclic ice accretion, melting, and shedding present in the realm of aircraft electrothermal de-icing systems. The
Domingos, Rodrigo, Becker, Gilberto
Numerical Modelling of Primary and Secondary Effects of SLD Impingement2019-01-200206/10/2019
A CFD simulation methodology for the inclusion of the post-impact trajectories of splashing/bouncing Supercooled Large Droplets (SLDs) and film detachment is introduced and validated. Several scenarios are tested to demonstrate how different parameters affect the simulations. Including re-injecting droplet flows due to splashing/bouncing and film detachment has a significant effect on the accuracy of the validations shown in the article. Validation results demonstrate very good agreement with the experimental data. This approach is then applied to a full-scale twin-engine turboprop to compute water impingement on the wings and the empennage. Since the performance characteristics of twin-engine commercial turboprops are such that they operate most efficiently at flight levels where SLD encounters may occur, the goal of this article is to establish a 3D computational methodology to eventually enable a complete study of the impact of FAR 25 Appendix O on the IPS requirements for this
Fouladi, Habibollah, Baruzzi, Guido S., Nilamdeen, Shezad, Ozcer, Isik
Photogrammetric Frost Roughness Measurements in Cold-Soaked Conditions2019-01-197006/10/2019
Cold-soaked fuel frost (CSFF) is a form of aircraft wing contamination that occurs when a vehicle caries sufficient fuel for multiple trips or take-offs and landings. Following the first trip, which may reach altitudes above 10,000 m (33,000 ft), the fuel for the subsequent trips is carried in the wing tanks and may reach temperatures below -25 °C. In certain times of the year at some airports, temperatures and humidity levels will form CSFF on the aircraft wing surfaces over the fuel tanks. Unless an exemption is granted for the specific aircraft model, aircraft are not allowed to takeoff if the wing surfaces are contaminated by frost. Because aircraft operators desire to minimize vehicle time spent at airports, aircraft manufacturers are expected to pursue designs that safely operate with CSFF at takeoff and to pursue certification exemptions for aircraft models enabling CSFF takeoffs. To assist manufacturers in the design of future aircraft and to assist regulators in evaluating
Miyauchi, Taber, McClain, Stephen T., Zhang, Tongxin, O'Neal, Dennis L., Riley, James T.
Experimental Aerodynamic Simulation of Glaze Ice Accretion on a Swept Wing2019-01-198706/10/2019
Aerodynamic assessment of icing effects on swept wings is an important component of a larger effort to improve three-dimensional icing simulation capabilities. An understanding of ice-shape geometric fidelity and Reynolds and Mach number effects on iced-wing aerodynamics is needed to guide the development and validation of ice-accretion simulation tools. To this end, wind-tunnel testing was carried out for 8.9% and 13.3% scale semispan wing models based upon the Common Research Model airplane configuration. Various levels of geometric fidelity of an artificial ice shape representing a realistic glaze-ice accretion on a swept wing were investigated. The highest fidelity artificial ice shape reproduced all of the three-dimensional features associated with the glaze ice accretion. The lowest fidelity artificial ice shapes were simple, spanwise-varying horn ice geometries intended to represent the maximum ice thickness on the wing upper surface. The results presented in this paper show
Broeren, Andy P., Potapczuk, Mark G., Lee, Sam, Woodard, Brian S., Bragg, Michael B., Smith, Timothy G.
Surface Contamination Effects on CRM Wing Section Model2019-01-197606/10/2019
The aerodynamic effects of Cold Soaked Fuel Frost have become increasingly significant as aircraft manufacturers have applied for to allow it during aircraft take-off. The Federal Aviation Administration and the Finnish Transport Safety Agency signed a Research Agreement in aircraft icing research in 2015 and started a research co-operation in frost formation studies, computational fluid dynamics for ground de/anti-icing fluids, and de/anti-icing fluids aerodynamic characteristics. The main effort has been so far on the formation and effects of CSFF. To investigate the effects a HL-CRM wing wind tunnel model, representing the wing of a modern jet aircraft, was built including a wing tank cooling system. Real frost was generated on the wing in a wind tunnel test section and the frost thickness was measured with an Elcometer gauge. Frost surface geometry was measured with laser scanning and photogrammetry. The aerodynamic effect of the frost was studied in a simulated aircraft take-off
Soinne, Erkki, Rosnell, Tomi
The Influence of SLD Drop Size Distributions on Ice Accretion in the NASA Icing Research Tunnel2019-01-202206/10/2019
An ice shape database has been created to document ice accretions on a 21-inch chord NACA0012 model and a 72-inch chord NACA 23012 airfoil model resulting from an exposure to a Supercooled Large Drop (SLD) icing cloud with a bimodal drop size distribution. The ice shapes created were documented with photographs, laser scanned surface measurements over a section of the model span, and measurement of the ice mass over the same section of each accretion. The icing conditions used in the test matrix were based upon previously used conditions on the same models but with an alternate approach to evaluation of drop distribution effects. Ice shapes resulting from the bimodal distribution as well as from equivalent monomodal drop size distributions were obtained and compared. Results indicate that the ice shapes resulting from the monomodal and bimodal drop size distributions had similar shapes, but the bimodal distributions had greater mass and volume measurements and icing limits that
Potapczuk, Mark G., Tsao, Jen-Ching
Evaluation of Visual Failure versus Aerodynamic Limit for a Snow Contaminated Anti-Iced Wing Section during Simulated Takeoff2019-01-197206/10/2019
Under contract to Airlines for America (A4A), APS Aviation Inc. (APS), in collaboration with the National Research Council of Canada (NRC), completed an aircraft ground icing exploratory research project at the NRC 3 m × 6 m Wind Tunnel in Ottawa in January 2019. The purpose of this project was to investigate the feasibility of using aerodynamic data to evaluate the performance of contaminated anti-icing fluid, rather than the traditional visual fluid failure indicators that are used to develop Holdover Times (HOTs). The aerodynamic performance of a supercritical airfoil model with anti-icing fluids and snow contamination was evaluated against the clean, dry performance of the airfoil in order to calculate the associated aerodynamic penalty. The visual failure of the fluid was also evaluated for each run, and the visual and aerodynamic results were compared against each other for each contamination exposure time. The results demonstrated that the visual failure of a fluid was not
Clark, Catherine, Ruggi, Marco
Multi-Shot Icing Simulations with Automatic Re-Meshing2019-01-195606/10/2019
A full-automated CFD mesh generation technique has been developed and implemented for 3-D aircraft icing simulations to permit robust 45-minute ice accretion simulations in support of icing certification campaigns. The changes in the shape of the aircraft surfaces due to accreting ice and their effects on the air and droplet flow are accounted for in a quasi-steady manner by subdividing the total icing time into sequential steps of shorter duration, updating the computational grid at each step. This “multi-shot” ice accretion approach requires robust and accurate grid re-meshing for it to be embedded in engineering design and analysis workflows. ANSYS FENSAP-ICE has been coupled to Fluent Meshing to take advantage of generic and highly automated surface displacement and mesh wrapping tools. A wide spectrum of geometries is supported, ranging from full-size aircraft to air data probes, turbomachinery components, rotors and propellers. With this technology, obtaining 45-minute ice shapes
Ozcer, Isik, Switchenko, David, Baruzzi, Guido S., Chen, Jian
A Study of Droplet Breakup in the Vicinity of an Airfoil2019-01-200006/10/2019
Supercooled large droplets can breakup before imping on aerodynamic surfaces and this should be taken into account in the icing codes. A study of droplets breakup in the vicinity of an airfoil has been conducted. Experiments for streams of droplets that were allowed to fall in the path of an incoming airfoil attached to a rotatory arm were conducted at the INTA facility. Droplets diameters ranged from 500 μm to 3 mm and two airfoils models of leading edge radius of 70 mm and 103 mm moving at velocities of 70 m/s, 80 m/s and 90 m/s were tested. Two subsets of experimental data for both bag and stamen breakup and shear breakup modes were used in this investigation. For these cases a numerical trajectory and deformation model was applied to obtain the evolution of the horizontal position, and the droplet maximum and minimum diameter. Breakup onset was determined from experimental data. Though previous works considered that breakup starts when there is a minimum in the minimum diameter
Sor, Suthyvann, Garcia-Magariño, Adelaida, Velazquez, Angel
An Experimental Study on the Effects of the Layout of DBD Plasma Actuators on Its Anti-/De-Icing Performance for Aircraft Icing Mitigation2019-01-203306/10/2019
Recently developed dielectric barrier discharge (DBD) plasma-based anti-icing systems have shown great potential for aircraft icing mitigation. In the present study, the ice accretion experiments were performed on to evaluate the effects of different layouts of DBD plasma actuators on their anti-/de-icing performances for aircraft icing mitigations. An array of DBD plasma actuators were designed and embedded on the surface of a NACA0012 airfoil/wing model in different layout configurations (i.e., different alignment directions of the plasm actuators (e.g., spanwise vs. streamwise), width of the exposed electrodes and the gap between the electrodes) for the experimental study. The experimental study was carried out in the Icing Research Tunnel available at Iowa State University (i.e., ISUIRT). While the dynamic anti-icing operation is recorded by using a high-resolution imaging system, a high-speed Infrared (IR) thermal imaging camera is used to quantitatively map the temperature
Kolbakir, Cem, Liu, Yang, Hu, Haiyang, Hu, Hui
Quantification of 3D Ice Structures Accreted on a Wind Turbine Airfoil Model2019-01-203006/10/2019
Accurate quantification of 3D shapes of the complex ice structures accreted on wind turbine blades is highly desirable to develop ice prediction models for more accurate prediction of the aerodynamic performance degradation and power reduction due to the ice accretion on wind turbine blades. In the present study, an experimental investigation was conducted to quantitatively characterize the 3D shapes of the ice structures accreted over a DU91-W2-250 wind turbine airfoil model in the Icing Research Tunnel available at Iowa State University (ISU-IRT). A glaze icing condition and a rime icing condition that wind turbines usually experience in winter were duplicated by using ISU-IRT. A high-resolution non-intrusive 3D scanning system was used to make detailed 3D-shape measurements to quantify the complicated ice structures accreted on the wind turbine airfoil model as a function of the ice accretion time. The measurements results show that the complex 3D shapes of the ice structures
Gao, Linyue, Veerakumar, Ramsankar, Liu, Yang, Hu, Hui
Motivation, Development and Verification of a Rapid 3D Lagrangian Impingement Code - Trajectory and Catch 3D+ (TAC3D+)2019-01-201106/10/2019
This paper details the motivation, development and validation of a rapid 3D Lagrangian impingement code, Trajectory and Catch 3D+ (TAC3D+). AeroTex’s motivation to develop a 3D Lagrangian method was primarily driven by the inherent mesh dependent dissipation effect found in their 3D Eulerian Water Catch code (EWC) [1]. Studies performed by AeroTex have shown that for geometries where there are aft impingement regions that are partly shadowed by a more forward impingement region, the level of water flux dissipation can be significant, particularly if the mesh is coarse and the impingement region is far aft. Examples of issues where this may be a particular issue would be impingement on a centerline aft mounted engine or the calculation of impingement on the wing root/belly fairing. The code has been developed around a modified version of the OpenFOAM Lagrangian solver. The analysis process consists of three main phases; a coarse droplet trajectory calculation to identify the region of
Roberts, Ian
An Explorative Study to Use Super-Hydrophilic/Super-Hydrophobic Hybrid Surfaces for Aircraft Icing Mitigation2019-01-199506/10/2019
An explorative study was performed to demonstrate the feasibility of using a novel hybrid anti-/de-icing strategy for aircraft icing mitigation. The hybrid method was developed by combining the electro-thermal heating mechanism and specialized surfaces/coatings with different wettabilities. While an electrical film heater was utilized to provide thermal energy around the leading edge of a NACA0012 airfoil model, two different coating strategies, (i.e., (a). Superhydrophobic coating covering the entire airfoil surface to increase droplets bounce-off and accelerate surface water runback vs. (b). super-hydrophilic coating at the leading edge to increase evaporation area + superhydrophobic coating in downstream to prevent runback refreezing) were proposed and evaluated aiming at maximizing the anti-/de-icing efficiency of the hybrid method. While a series of experiments were conducted to examine the dynamics of droplet impinging onto the different surfaces (i.e., superhydrophobic vs. super
Hu, Haiyang, Hu, Hui, Liu, Yang
Numerical Analysis of Asymmetric Canard-Wing System in Detroit Flying Cars2019-01-136103/19/2019
A numerical simulation system of airflow around the Detroit Flying Cars-Wild Dream 1 (WD-1) is introduced. It involves the application of FVM, the mesh-independence system, boundary conditions and the verification of the simulation conditions to NACA airfoil data and the discussion of technological treatments corresponding to the evaluation of asymmetric wings. The present work is investigating the aerodynamic behavior of an asymmetric canard-wing system used on the Detroit Flying Cars-WD 1 model. The work involves the application of Finite Volume Method (FVM), the mesh-independence system, boundary conditions and the verification of simulation conditions to NACA airfoil data using OpenFOAM software. The Reynolds number based on free stream velocity and root chord is 5X106. Based on the Coefficient of Lift and Coefficient of Drag obtained from the analysis, the effect of canards on the wings, the distance between the canard trailing edge and the leading edge of the wings and the
Kocherla, Isaac Shanth, Yu, ChenXing
Design of a Wing for Formula One Category Airplanes2019-01-133703/19/2019
This paper describes the design of an International Formula One (IF1) racing airplane wing. The first step consists in the simulation of the airplane flying on the race track to obtain details about the condition in which the wing needs to be designed and optimized. The paper describes the details and formulation used to perform this simulation using parametric flight paths and a point model dynamic model. A scheme analytically obtains the control laws for the simulation with Frenet-Serret frames over the parametric flight path. Two different airplanes, with different power levels, are simulated on a typical IF1 race track to determine the range of lift coefficient in which the wing must be designed. Based on this lift coefficient range, a set of four new airfoils are designed based on the NLF0414-F airfoil. Their usage over the wing span is determined, using nonlinear lifting line method to assure that during races the wing operates inside the laminar drag bucket. Finally, this paper
Andrade de Oliveira, Paulo Henriques Iscold
Axiomatic Design of a Reconfigurable Assembly System for Aircraft Fuselages2019-01-135903/19/2019
Modern aerospace industry develops assembly process lines for new aircraft which is produced on a single production line while shortening production times by new technologies. Production processes are developed with systems such as lightweight fixtures, reconfigurable tools, automated part positioning, automated scanning countersink control, automated riveting, robotic measurement etc. These systems provide the necessary flexibility for aircraft fuselage and wing assembly projects. Aerospace manufacturers invest in assembly lines in order to increase production rates and meet growing customer demands. Most of the investments are allocated to state-of-the-art robots for drilling and riveting, sealing, coating and painting applications, in addition to material handling, carbon fiber layup and different types of machining operations. In this study, an assembly system design methodology is developed by using axiomatic design principles in order to propose a solution to design complexity
Celek, Osman Emre, Yurdakul, Mustafa, Ic, Tansel
Design, Manufacturing, Testing, and Analysis of a Highly-Constrained Single-Use UAV Wing2018-01-195810/30/2018
Unmanned aerial vehicle (UAV) design aspects are as broad as the missions they are used to support. In some cases, the UAV mission scope can impose design constraints that can be difficult to achieve. This paper describes recent work performed at West Virginia University (WVU) to support repeated flight testing of a single-use UAV platform with emphasis on the highly specialized wings required to help meet the overall airframe mass properties constrained by the project sponsor. The wings were fabricated using a molded polyurethane (PU) foam as the base material which was supported by several different types of rigid and flexible substructures, skins, and matrix-infused fiber elements. Different ratios of infused fiber mass to PU foam were tested and additional tungsten masses were added to the wings to achieve the correct total mass and mass distribution of the wings. Expected accelerations were applied to the wing designs analytically and numerically to establish appropriate test
Browning, Patrick H., Hubbard, Levi S., Pennock, Philip
Design, Development and Integration of a Wing-Morphing, Bimodal Unmanned Vehicle2018-01-196010/30/2018
This paper relates to the design and development of a multi-modal UAV capable of aerial flight and underwater propulsion. A novel hybrid propulsion system has been manufactured and tested. Consisting of folding blades, the propeller has been optimized for propulsion both in air and water. The critical water to air transition phase is achieved by an additional impulsive thruster powered by a C02 cartridge. To decrease the drag in underwater cruise and reduce the potential damage when the vehicle impacts the water, a morphing wing has been developed. This consists of foam-carbon fiber lay-up constructed wings in a variable sweep configuration. The actuation of the sweep is achieved by linear servos mounted on the sleeve shaped spar. An integrated prototype is constructed, using an unconventional, anhedral horizontal stabilizers to allow clearance for the morphing wing. Using a combination of data taken from wind tunnel testing, CFD simulation and analytic methods, models of the vehicles
Simpson, Mark, Guo, Dian
Highly Efficient Civil Aviation, Now via Operations - AAR and Challenges2018-01-192510/30/2018
Global civil aviation growth at 5+% yearly poses extreme environmental challenges. Advances have appeared gradually through improved aerodynamic shapes, using carbon fibres, and enhanced engines; however, as these technologies mature, direct efficiency advances require increasing effort. Often Passenger convenience is forgotten e.g. the long-range air traffic has developed on hub-spoke basis implying extra feeder flights, transit passenger inconveniences, capacity issues. Efficiency metrics emphasize “Why, How & What”, with an understanding of the range sensitivities, operational concepts and performance goals via the important “X-factor”. For given range, current aircraft are “greener” than previous generations. Medium range aircraft s are always greener than those for short or long ranges. However, currently, the major trend is for the latter: twin-aisle A350, A380, B787, B777X (10+% payload, 40+% fuel to MTOW). Shorter range single-aisle aircraft are “feeders” or newer derivatives
Nangia, R K
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