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An Experimental Study of Atmospheric Icing Process on Power Transmission Line

Iowa State University-Ramsankar Veerakumar, Linyue Gao, Yang Liu, Hui Hu
  • Technical Paper
  • 2019-01-2019
To be published on 2019-06-10 by SAE International in United States
Atmospheric icing poses a major threat to power transmission lines in cold regions. In the present study, an experimental investigation was conducted to examine the atmospheric icing process on high-voltage power transmission lines and characterize the effects of the ice accretion on the aerodynamic forces acting on the transmission lines. The experimental study was conducted in the Icing Research Tunnel available at Iowa State University(ISU-IRT). A cylinder model with the same diameter of commonly-used high-voltage power transmission lines (i.e., D = 29mm) is subjected to a typical glaze icing condition at an incoming wind speed of 20 m/s, a liquid water content (LWC) of 2.0 g/m3 and an ambient temperature of -5 ⁰C. A high-resolution 3D scanner was used in the present study to extract the 3D shapes of the ice structures accreted over surface of the cylindrical test model as a function of the ice accretion time. While the aerodynamic drag force acting on the test model was measured by using a force transducer during the dynamic ice accreting process, a high-resolution Particle Image…
 

Numerical Simulation of Aircraft and Variable-Pitch Propeller Icing with Explicit Coupling

ANSYS Inc.-Isik Ozcer, Guido S. Baruzzi, Miraj Desai, Maged Yassin
  • Technical Paper
  • 2019-01-1954
To be published on 2019-06-10 by SAE International in United States
A 3D CFD methodology is presented to simulate ice build-up on propeller blades exposed to known icing conditions in flight, with automatic blade pitch variation at constant RPM to maintain the desired thrust. One blade of a six-blade propeller and a 70-passenger twin-engine turboprop are analyzed as explicitly-coupled stand-alone components in a multi-shot quasi-steady icing simulation. The thrust and swirl produced by the propellers provide the loading distribution for their actuator disk surrogates mounted on the aircraft. The thrust that must be generated by the propellers is obtained from the drag computed on the aircraft. The total icing exposure time is subdivided into 30-second shots. The flight conditions are typical for a 70-passenger twin-engine turboprop in a holding pattern in Appendix C icing conditions: 190 kts, altitude 6,000 ft, air static temperature -16 ˚C, LWC 0.3 g/m3 and MVD 20 microns. The iced geometries are automatically remeshed at each shot using ANSYS FENSAP-ICE and Fluent Meshing tools. Solutions for the 2-meter blade are computed in a periodic domain to reduce computational costs. The pitch variation…
 

An Experimental Study on the Dynamic Ice Accretion Processes on Bridge Cable Models with Different Surface Modifications

Harbin Institute of Technology-Wenli Chen
Iowa State University-Yang Liu, Yihua Peng, Hui Hu
  • Technical Paper
  • 2019-01-2018
To be published on 2019-06-10 by SAE International in United States
An experimental study was conducted to investigate the dynamic ice accretion processes on bridge cable models with different surface modifications (i.e., Standard plain, Pattern-indented surface, and helical fillets). The icing experiments were performed in the unique Icing Research Tunnel available at Iowa State University (i.e., ISU-IRT). In order to reveal the transient ice accretion processes and the associated aerodynamic loadings on the test models under different icing conditions (i.e., rime vs. glaze), while a high-speed imaging system was used to capture the transient features of the surface water runback and ice accretion over the surface of the cable models, a high-accuracy dual-transducer force measurement system was also utilized to measure the dynamic aerodynamic loadings acting on the ice accreting cable models. It was found that, the addition of surface features (i.e., pattern-indented surface vs. helical fillets) could effectively influence the dynamic ice accretion process and the final ice structures. Based on the temporally-resolved measurements of the aerodynamic drag forces acting on the different cable models, it was found that, while the ice accretion on the…
 

Lattice Boltzmann Simulations of Flow Over an Iced Airfoil

Dassault Systemes-Rafael Ihi, Andre Ribeiro
Embraer-Luis Santos, Daniel Silva
  • Technical Paper
  • 2019-01-1945
To be published on 2019-06-10 by SAE International in United States
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 using periodic boundary condition. 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 and profiles, 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 two experimental data. Velocity and turbulence intensity contours as well as stagnation streamlines enabled a more detailed comparison of the flowfield, which showed great accuracy of the simulations to predict the reattachment location. Overall, very good agreement is obtained with the available reference data. The numerical tool used to calculate the aerodynamic…
 

Non-spherical Particle Trajectory Modelling for Ice Crystal Conditions

AeroTex UK-Ian Roberts, Richard Moser, Colin Hatch
University College London-Ryan Palmer, Frank Smith
  • Technical Paper
  • 2019-01-1961
To be published on 2019-06-10 by SAE International in United States
Aircraft icing is a significant issue for aviation safety. We use recent developments for calculating the drag, lift and torque correlations for four specific particle shapes to determine the trajectory, rotation and impingement of ice particles in aircraft icing scenarios. Previously, within the range of Reynolds number permitted in this study, it was only possible to model the trajectory and rotational progression of cylindrical particles. The work presented in this paper allows for analysis of a wider range of ice shapes that are commonly seen in icing conditions, capturing the dynamics and behaviours specific to these particles. Previous limitations relating to the dependency of drag, lift and torque coefficients on the measure of sphericity are overcome. The method provides an opportunity for new analysis. As seen through our analysis, taking the worst and best case scenarios provides a range of values for the catch, which can help to understand the extent to which particles impinge and where. Hence a catch-limit for a mixed cloud of particles of different shaped particles and different sized particles may…
 
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F1 STREAMLINES FOR CLOSER RACING

Dan Carney
  • Magazine Article
  • 19AUTP05_05
Published 2019-05-01 by SAE International in United States

In the downforce vs. turbulence battle, Formula 1 enacts technical changes to rev up the on-track spectacle.

Ongoing aerodynamic development of Formula 1 racecars has the most obvious goals of increasing the cars' downforce and reducing their drag to produce the fastest speeds and quickest lap times.

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Monitoring a Nearshore Beneficial Use Site: Application of a Benthic Sled and Video Annotation

  • Magazine Article
  • 19AERP05_07
Published 2019-05-01 by SAE International in United States

Passive survey method provides less labor and resource intensive system for monitoring the effects of dredging on aquatic life in nearshore beneficial use sites.

The U.S. Army Corps of Engineers (USACE) Portland Districts (NWP) maintains safe and navigable waterways in Oregon through a variety of dredging projects, including channel deepening, and dredging sandbars. Placement of dredged sediment occurs at preselected, specific geographic areas categorized as nearshore beneficial use sites. Beneficial use sites are commonly monitored before, during, and after disposal, to evaluate dredge management practices and to avoid potentially adverse effects to the marine environment.

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Multidisciplinary Design Analysis and Optimization of Aerospace Composites

Charles Lu
  • Progress In Technology (PT)
  • PT-201
Published 2019-04-30 by SAE International in United States
Multidisciplinary Design and Optimization of Aerospace Composite Materials is a collection of ten SAE technical papers focusing on the design analysis of aerospace composite structures from the perspective of various disciplines. The book concentrates on the following aspects: • Analytical methods for weight design of aircraft structures, including a parametric geometry model capable of generating dedicated models for both aerodynamic and structural solvers. • Methodologies for evaluating the structural performance of carbon/epoxy composite panels. • An aerodynamic design of flexible wings made of composite structures. • Thermal design and analysis of composite enclosures. • Methodologies for analyzing the acoustic performance of composite structures, including the design optimization method to evaluate the acoustic performance in terms of transmission loss (TL) of various composite panels. • The lightening effect on composites, presenting a theoretical method to compute the electrical current propagating through composite structures due to lightning strikes. • The issue of fire resistance as most polymer resins are flammable once the respective ignition temperatures are reached. • A probabilistic-based reliability analysis of the composite structures. The…
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Vehicle Aerodynamic Optimization: On a Combination of Adjoint Method and Efficient Global Optimization Algorithm

China Automotive Technology and Research Center Co., Ltd, China-Jing Li, Chen Xu
Hebei University of Technology, China China Automotive Technology and Research Center Co., Ltd, China-Yang Zhang
  • Journal Article
  • 06-12-02-0011
Published 2019-04-26 by SAE International in United States
This article presents a workflow for aerodynamic optimization of vehicles that for the first time combines the adjoint method and the efficient global optimization (EGO) algorithm in order to take advantage of both the gradient-based and gradient-free methods for aerodynamic optimization problems. In the workflow, the adjoint method is first applied to locate the sensitive surface regions of the baseline vehicle with respect to the objective functions and define a proper design space with reasonable design variables. Then the EGO algorithm is applied to search for the optimal site in the design space based on the expected improvement (EI) function. Such workflow has been applied to minimize the aerodynamic drag for a mass-produced electric vehicle. With the help of STAR-CCM+ and its adjoint solver, sensitive surface regions with respect to the aerodynamic drag are first located on the vehicle. Then the design samples are determined with the help of the uniform design (UD) method and trained by the EGO algorithm (written by MATLAB) for searching the optimum. The optimization results are analyzed to validate the…
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Test Procedure for Determining the Resistance of Safety-Glazing Materials, of which One Surface is Plastic, to Simulated Weathering

Glazing Materials Standards Committee
  • Ground Vehicle Standard
  • J2081_201904
  • Current
Published 2019-04-11 by SAE International in United States

This SAE Recommended Practice determines whether plastic and glass-plastic safety glazing materials will successfully withstand exposure to simulated weathering conditions.