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Semi-Empirical Modelling of Erosion Phenomena for Ice Crystal Icing Numerical Simulation

ONERA-Virgile Charton, Pierre Trontin, Philippe Villedieu
SAFRAN Aircraft Engines-Gilles Aouizerate
Published 2019-06-10 by SAE International in United States
The aim of this work is to develop a semi-empirical model for erosion phenomena under ice crystal condition, which is one of the major phenomena for ice crystal accretion. Such a model would be able to calculate the erosion rate caused by impinging ice crystals on accreted ice layer.This model is based on Finnie [1] and Bitter [2] [3] solid/solid collision theory which assumes that metal erosion due to sand impingement is driven by two phenomena: cutting wear and deformation wear. These two phenomena are strongly dependent on the particle density, velocity and shape, as well as on the surface physical properties such as Young modulus, Poisson ratio, surface yield strength and hardness. Moreover, cutting wear is mostly driven by tangential velocity and is more effective for ductile eroded body, whereas deformation wear is driven by normal velocity and is more effective for brittle eroded body. Several researchers based their erosion modelling on these two phenomena such as Hutchings et al. [4] for deformation erosion, or Huang et al. [5] and Arabnejad et al. [6]…
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Process Regulations and Mechanism of WEDM of Combustor Material

National Institute of Technology, Kurukshetra, India-Bhupinder Singh, Joy Prakash Misra
  • Journal Article
  • 01-12-01-0004
Published 2019-06-07 by SAE International in United States
This study discusses the experimental investigation on WEDM of combustor material (i.e., nimonic 263). Experimentation has been executed by varying pulse-on time (Ton), pulse-off time (Toff), peak current (Ip), and spark gap voltage (Sv). Material removal rate (MRR), surface roughness (SR), and wire wear rate (WWR) are employed as process performance characteristics. Experiments are designed as per the box-Behnken design technique. Parametric optimization has also been performed using response surface methodology. Besides this, field-emission scanning electron microscope (FE-SEM) and an optical microscope are utilized to characterize WEDMed and worn-out wire surfaces. It is observed that both surfaces contain micro-cracks, craters, spherical droplets, and a lump of debris. Furthermore, the mechanism of recast layer formation has been critically evaluated to apprehend a better understanding of the technique. The key features of the experimental procedure are also highlighted.
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Modeling of Micro-Perforated Heat Baffle

California State University- Long Beach-Allen Teagle-Hernandez
HSEA Technology, Inc.-Takehisa Matsuda
Published 2019-06-05 by SAE International in United States
Classical porous materials are used throughout the automobile with usually good success but there are limitations to their performance in areas where there are adverse environments. An example of this is the transmission tunnel section under the automobile, where there exist high air flow velocities and temperatures which will lead to quick deterioration of the material. Micro-Perforated Heat Baffles (MPHB) are showing success in the heating, ventilating, and air conditioning industry, and therefore there is an effort in applying MPHB extensively in the automotive field. The question with regards to which micro-perforation pattern gives the best performance plus where and how much should be allocated in the automobile still remains. This paper shows how to address these issues by applying Hybrid Statistical Energy Analysis (HSEA) technology. An expression for the Absorption Coefficient (AC) which incorporates the micro-perforation pattern is explained. This equation models the absorption of sound due to friction losses in the holes. Thereafter calculations for flat sample AC are completed and good correlation with experimental data is shown. Flat sample AC is necessary…
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Rotary Electrical Contact

  • Magazine Article
  • TBMG-34620
Published 2019-06-01 by Tech Briefs Media Group in United States

Researchers have developed a fundamentally new type of rotary electrical contact that addresses the two limitations of conventional brush/slip ring technology: 1) short operating lifetime due to sliding-contact wear, and 2) electrical arcing associated with contact bounce.

 
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Aircraft Fueling Adapter Wear Limits

AE-5C Aviation Ground Fueling Systems Committee
  • Aerospace Standard
  • ARP5298
  • Current
Published 2019-05-15 by SAE International in United States
This SAE Aerospace Recommended Practice (ARP) defines the wear limits allowed on certain features of Pressure Fuel Servicing Adapters which are crucial for safe interfacing of Pressure Fuel Servicing Nozzles and Pressure Caps. Wear limits as described herein represent the maximum amount of wear on certain features of the Adapter beyond which use of the Adapter for these purposes may contribute to an unsafe condition. Such wear is the result of the normal use of the Adapter for aircraft refueling and also, in some cases, for Nozzle stowage on refueling vehicles.
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Environmental Degradation of Textiles

AGE-2 Air Cargo
  • Aerospace Standard
  • AIR1490C
  • Current
Published 2019-04-24 by SAE International in United States
Since cargo restraint devices made with textiles should have a predictable service life, there should be data available so that predictions can be made. This document compiles available information on textiles of the types used in air cargo restraint devices and reviews the degradation characteristics of each. Textiles are used primarily in cargo restraint nets on air cargo pallets and nonstructural containers, restraint nets installed in cargo aircraft, and similar applications.
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Volumetric Rating of Excavator Mounted, Bucket Linkage Operated Grapples

MTC C5, Excavators
  • Ground Vehicle Standard
  • J2754_201904
  • Current
Published 2019-04-15 by SAE International in United States
No Abstract Available.
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Compensation Strategies for Aging Effects of Common-Rail Injector Nozzles

Technical University of Munich-Sebastian Schuckert, Mark Huthmacher, Georg Wachtmeister
Published 2019-04-02 by SAE International in United States
The thermal and emission efficiency of diesel engines depends to a large extent on the quality of fuel injection. However, over engine lifetime, injection rate and quality will change due to adverse nozzle aging effects, such as coking or cavitation. In this study, we discuss the influences of these effects on injection and heat release rate. The injection rates of previously unused nozzles and a nozzle that had been operated in a vehicle engine were compared in order to clarify the impact of aging effects. The key to the detection of alterations of injection nozzles is the identification of strongly correlating parameters. As a first step, an instrumented injector was set up to measure fuel pressure inside the feed line of the injector and the lift of the control piston. Different nozzles showed a distinguishable control piston motion depending on their different geometric specifications, which also affect the injection rates. In a second step, engine simulations were performed to investigate the impact of nozzle aging on heat release rate and engine performance of a single-cylinder…
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Life Estimation of Rolling Bearings Based on the Colors on Sliding Surfaces

Honda R&D Co., Ltd.-Yuki Ono, Kenji Matsumoto
Tokyo City University-Yuji Mihara
Published 2019-04-02 by SAE International in United States
It is experimentally known that the surface color of bearing balls gradually becomes brown during long term operation of the bearings under appropriate lubrication conditions. That exhibits the possibility of an estimation method for residual life of ball bearings without any abnormal wear on the surfaces by precise color measurements. Therefore, we examined what set colors on bearing balls by surface observation using scanning electron microscopy and subsurface analysis using transmission electron microscopy. Results showed that an amorphous carbon layer had gradually covered ball surfaces during operation of the bearings. The layer not only changed ball color but also made overall ball shapes closer to a complete sphere. The report also introduces a uniquely developed color analyzer which enabled color measurements on metallic surfaces, such as the above-mentioned balls.
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Durability Study of a High Pressure Common Rail Fuel Injection System Using Lubricity Additive Dosed Gasoline-Like Fuel - Additional Cycle Runtime and Teardown Analysis

Aramco Research Center - Detroit-Tom Tzanetakis, Michael Traver, Vincent Costanzo
Argonne National Laboratory-Katarzyna Matusik, Brandon Sforzo, Alan Kastengren, Christopher Powell
Published 2019-04-02 by SAE International in United States
This study is a continuation of previous work assessing the robustness of a Cummins XPI common rail injection system operating with gasoline-like fuel. All the hardware from the original study was retained except for the high pressure pump head and check valves which were replaced due to cavitation damage. An additional 400 hour NATO cycle was run on the refurbished fuel system to achieve a total exposure time of 800 hours and detect any other significant failure modes. As in the initial investigation, fuel system parameters including pressures, temperatures and flow rates were logged on a test bench to monitor performance over time. Fuel and lubricant samples were taken every 50 hours to assess fuel consistency, metallic wear, and interaction between fuel and oil. High fidelity driving torque and flow measurements were made to compare overall system performance when operating with both diesel and light distillate fuel. Injector rate shapes were measured as a function of time, and high resolution x-ray imaging of the nozzle tips was performed as part of the final teardown analysis.…
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