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 Packer

TBMG-3759909/01/2020

Kaman UK Darwen, UK +44 1254 706000

CAD-Based Optimization of a Race Car Front Wing

2020-01-062404/14/2020

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

Simulation of Transient On-Road Conditions in a Closed Test Section Wind Tunnel Using a Wing System with Active Flaps

2020-01-068804/14/2020

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

Application of Extended Messinger Models to Complex Geometries

2020-01-002203/10/2020

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

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

New Airplane Wing Assembled from Tiny Identical Pieces

TBMG-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 Tooling

2019-01-188009/16/2019

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 Configuration

2019-01-188409/16/2019

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

Low Cost Reconfigurable Jig Tooling and In-Process Metrology for High Accuracy Prototype Rotorcraft Wing Assembly

2019-01-187709/16/2019

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

Landing Gear Integration into Aircraft Structure in Early Design Stage

2019-01-189009/16/2019

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 Structure

2019-01-191609/16/2019

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

3D Optical Scanner

TBMG-3511609/01/2019

NVision, Inc. Southlake, TX 817-416-8006

A Study of Droplet Breakup in the Vicinity of an Airfoil

2019-01-200006/10/2019

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

Experimental Aerodynamic Simulation of Glaze Ice Accretion on a Swept Wing

2019-01-198706/10/2019

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.

Quantification of 3D Ice Structures Accreted on a Wind Turbine Airfoil Model

2019-01-203006/10/2019

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 Mitigation

2019-01-199506/10/2019

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

Lattice Boltzmann Simulations of Flow Over an Iced Airfoil

2019-01-194506/10/2019

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

Surface Contamination Effects on CRM Wing Section Model

2019-01-197606/10/2019

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

Separating-Reattaching Flows Over an Iced Airfoil

2019-01-194606/10/2019

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

An Experimental Study on the Effects of the Layout of DBD Plasma Actuators on Its Anti-/De-Icing Performance for Aircraft Icing Mitigation

2019-01-203306/10/2019

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

Computational Simulation of an Electrically Heated Ice Protection System for Composite Leading Edges of Aircraft

2019-01-204106/10/2019

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

The Influence of SLD Drop Size Distributions on Ice Accretion in the NASA Icing Research Tunnel

2019-01-202206/10/2019

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

Numerical Modelling of Primary and Secondary Effects of SLD Impingement

2019-01-200206/10/2019

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

On-Ground Cold Soak Fuel Frost Modeling

2019-01-1975

06/10/2019

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