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2015-09-29
Technical Paper
2015-01-2869
Sumit Sharma, Sandeep Sharma, Umashanker Gupta, Ravi Joshi, Shailesh Pawar
Buses are one of the main and favorite sources of public transit in India. Thousands of people die or injure severely every year due to Bus accidents. Passenger injury in Bus accidents can be due to high stiff seat structures. Most of the occupants seated in the second row or further back were injured by hitting the seat back in the row in front of them. AIS023 (AUTOMOTIVE INDUSTRY STANDARDS) is one of the several mandatory standards from CMVR (CENTRAL MOTOR VEHICLES RULES) to ensure the safety during crash. As per AIS-023 passenger seat of bus should not cause injury because of high stiffness, on the other hand seat should also be able to carry the passenger force during accidents. With this mechanism AIS023 specifies minimum and maximum range deformations of seat back to minimize the passenger injury. This study includes the FE (Finite Element) analysis and design of Bus seat as per AIS023 test setup with LS-Dyna explicit tool.
2015-09-29
Journal Article
2015-01-2817
Matthew Goertz, Lloyd Tull, Davis Moravec
Abstract The winter of 2013-2014 provided an opportunity to operate off-road vehicles in cold weather for extended time as part of a vehicle/tier 4 diesel engine validation program. An unexpected area of study was the performance of high efficiency, on engine, fuel filters during continuous vehicle operation in cold weather. During the program we observed unexpected premature fuel filter plugging as indicated by an increase in pressure drop across the filter while in service. Field and laboratory testing was completed at John Deere and Donaldson to understand the cause of filter plugging. Although conditions were found where winter fuel additives could cause plugging of high efficiency filters, premature filter plugging occurred even when testing with #1 diesel fuel. This fuel contained no additives and was used at temperatures well above its cloud point.
2015-09-29
Technical Paper
2015-01-2838
Dharmar Ganesh, Riyaz Mohammed, Hareesh Krishnan, Radakrishnan Rambabu
In-vehicle displays such as an instrument cluster in a vehicle provide vital information to the user. The information in terms of displays and tell-tales needs to be perceived by the user with minimal glance during driving. Drivers must recognize the condition of the vehicle and the state of its surroundings through primarily visual means. Drivers then process this in the brain, draw on their memory to identify problem situations, decide on a plan of action and execute it in order to avoid an accident. There are visual hindrances seen in real world scenario such as obscuration, reflection and glare on the instrument cluster which prevents the vital information flow from vehicle to the driver. In order to ensure safety while driving, the instrument cluster or driver displays should be placed in an optimized location. This paper deals with how to achieve a visual hindrance free cluster position in a vehicle to protect the important information flow from the vehicle to the driver.
2015-09-15
Technical Paper
2015-01-2441
Ahmet Oztekin
Air Traffic Control System (ATCS) provides organizational, operational, and technical infrastructure necessary to maintain air traffic separation and prevent collision between aircraft operating within civil airspace. Current aviation safety research focuses mainly on aircraft and human vs. machine interactions. There is a gap in literature regarding research that explores ATCS’s potential impact on aviation safety. For complex systems, such as ATCS, safety is primarily a product of potential interactions among its various sub-systems. For example, over the phases of flight, separation of air traffic is maintained by different types of air traffic control (ATC) facilities. This paper outlines an analytical framework to perform a data-driven, risk-based assessment of ATC facilities. Safety associated with an ATC facility is modeled as an influence network using a set of risk factors.
2015-09-15
Journal Article
2015-01-2385
Richard C. Millar
Abstract Unmanned aviation systems (UAS) acquired for US Navy for military roles are developed in the context of NAVAIR's rigorous and well-established policies, procedures and processes employed in the acquisition and development of manned aircraft. A key process is the preparation and approval of interim flight clearances (IFC) prior to flight test to ensure the aircraft is airworthy and thus safe to operate. Due to the perceived risks of UAS experimental flight test, the use of this process has been mandated for all Navy organizations, including use of commercially available UAS in research projects. This policy has proved to be a challenge, impeding and discouraging the use of UAS in research and experimental projects. Currently, the cost of compliance is unaffordable and IFC preparation and approval time are inconsistent with research cycle time expectations.
2015-09-01
Magazine
Driving EVs toward lower cost The race is on to reduce battery and electric-drive systems costs while improving efficiency. Seeking ways to make better computer crashes New models and simulations help improve safety as software and hardware provide more realism to iterate designs more quickly. Evaluating aluminum bonds Adhesively joined aluminum alloy sheets present challenges that steel-adhesive joints do not. Ford researchers present a modified technique to inspect Al-adhesive joints in lab and production environments. Leading the attack on engine pumping losses Cylinder deactivation delivers real-world fuel economy gains, helping vehicles to meet and exceed their sticker numbers. That's why the downsized/boosted guys now want it on their engines.
2015-08-27
Standard
J2418_201508
This SAE Recommended Practice describes the test procedures for conducting frontal impact restraint tests for heavy truck applications. Its purpose is to establish recommended test procedures that will standardize restraint system testing for heavy trucks. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included.
2015-08-07
Standard
AS5562
This SAE Aerospace Standard (AS) establishes minimum ice and rain performance criteria for electrically-heated pitot and pitot-static probes intended for use on the following classes of fixed-wing aircraft and rotorcraft. The classes of fixed-wing aircraft are defined by aircraft flight envelopes and are shown in Figure 1. The flight envelopes generally fall into the classes as shown below: Class 1: Cruise altitude ≤ 23 000 feet Class 2: Cruise altitude ≤ 31 000 feet Class 3: Cruise altitude ≤ 42 000 feet Class 4: Cruise altitude > 42 000 feet Class R: Rotorcraft The user of this standard must evaluate the aircraft level installation requirements for the probe against the class definition criteria to ensure adequate coverage for the application. It may be necessary to step up in class or modify the test conditions in order to meet the applicable installation requirements. NOTE: Class 2 is divided into two subgroups identified as either Class 2a or Class 2b.
2015-07-22
Standard
J2779_201507
This procedure establishes a recommended practice for performing a Low Speed Thorax Impact Test to the Hybrid III 50th Male Anthropomorphic Test Device (ATD or crash dummy). This test was created to satisfy the demand by the industry to have a calibration test which resulted in similar results to an actual low energy automotive impact test. An inherent problem exists with the current calibration procedure because the normal (6.7 m/s) thorax impact test has test corridors that are not representative to these low energy impact tests. The normal test corridors specify a displacement range of around 68 mm and the low speed displacement corridor needs to be around 25 mm. The intent of this recommended practice is to develop a low speed thorax calibration procedure for the H-III50M dummy in 25 to 30 mm deflection range.
2015-07-09
WIP Standard
AIR6341
The purpose of this AIR is to compile in one definitive source, commonly accepted calibration, acceptance criteria and procedures for simulation of Supercooled Large Droplet (SLD) conditions within icing wind tunnels. Facilities that meet the criteria for either some or all of the recognized conditions will have known SLD icing simulation capability.
2015-06-15
Technical Paper
2015-01-2112
Thomas Schlegl, Michael Moser, Hubert Zangl
Abstract We present a wireless sensor system for temperature measurement and icing detection for the use on aircraft. The sensors are flexible (i.e. bendable), truly wireless, do not require scheduled maintenance, and can be attached easily to almost any point on the aircraft surface (e.g. wings, fuselage, rudder, elevator, etc.). With a sensor thickness of less than two millimeters at the current state of development, they hardly affect the aero dynamical behavior of the structure. In this paper, we report laboratory and field results for temperature measurement and icing detection.
2015-06-15
Technical Paper
2015-01-2082
Andreas Tramposch, Wolfgang Hassler, Reinhard F.A. Puffing
Abstract Certain operating modes of the Environmental Control System (ECS) of passenger aircraft are accompanied with significant ice particle accretion in a number of pivotal parts of the system. Icing conditions particularly prevail downstream of the air conditioning packs and, as a consequence, ice particle accretion takes place in the Pack Discharge Duct (PDD) and in the mixing manifold. For a better understanding of these icing processes, numerical simulations using a multiphase model based on a coupled Eulerian-Lagrangian transport model in a generic PDD were performed. The obstruction of the PDD due to ice growth and the resulting change of the flow geometry were treated by deforming the computational mesh during the CFD simulations. In addition to the numerical investigations, a generic and transparent PDD was studied experimentally under several operating conditions in FH JOANNEUM's icing wind tunnel.
2015-06-15
Technical Paper
2015-01-2081
Hossein Habibi, Graham Edwards, Liang Cheng, Haitao Zheng, Adam Marks, Vassilios Kappatos, Cem Selcuk, Tat-Hean Gan
Abstract Icing conditions in cold regions of the world may cause problems for wind turbine operations, since accreted ice can reduce the efficiency of power generation and create concerns regarding ice-shedding. This paper covers modelling studies and some experimental development for an ongoing ice protection system that provides both deicing and anti-icing actions for wind turbine blades. The modelling process contained two main sections. The first part involved simulation of vibrations with very short wavelength or ultrasonic guided waves (UGW) on the blade to determine optimal excitation frequency and transducer configuration. This excitation creates horizontal shear stress at the interface between ice and blade and focuses energy at the leading edge for de-bonding ice layers.
2015-06-15
Technical Paper
2015-01-2080
Roger J. Aubert
Abstract The entire process from ice accretion to ice impact with ice shedding in between still needs refinement. This paper presents key points illustrating the need for improvements in understanding the mechanical properties of ice accretion on helicopter rotor systems.
2015-06-15
Technical Paper
2015-01-2079
Colin Hatch, Jason Moller, Eleftherios Kalochristianakis, Ian Roberts
Abstract The introduction of ice-phobic coatings promises to allow passive ice protection systems to be developed particularly for rotating systems such as propellers. The centrifugal force field combined with reduced adhesive strength can produce a self-shed capability limiting the amount of ice build-up. The size and shed time of ice shed from a propeller is predicted using a process that determines ice shape, ice growth rate and both internal and ice-structure interface stresses. A simple failure model is used to predict the onset of local failure and to propagate damage in the ice until local ice shedding is obtained. Recommendations are made on developing the model further.
2015-06-15
Technical Paper
2015-01-2078
Alric Rothmayer, Hui Hu
Abstract A strong air/water interaction theory is used to develop a fast simplified model for the trapping of water in a film that flows over sub-grid surface roughness. The sub-grid model is used to compute correction factors that can alter mass transport within the film. The sub-grid model is integrated into a covariant film mass transport model of film flow past three-dimensional surfaces in a form that is suitable for use in aircraft icing codes. Sample calculations are presented to illustrate the application of the model.
2015-06-15
Technical Paper
2015-01-2076
Caroline Laforte, Neal Wesley, Marc Mario Tremblay
Abstract This study presents a new method to evaluate and compare the anti-icing performance, i.e., the ability to delay the reformation of ice, of runways and taxiways deicing/anti-icing fluids (RDF) under icing precipitation, based on the skid resistance values, obtained with the Portable Skid Resistance Tester (PSRT). In summary, the test consists of applying, on a standardized concrete pavement sample, a given quantity of de-icing fluid. Following this application, the concrete sample is submitted to low freezing drizzle intensities, in a cold chamber at −5.0 ± 0.3°C. The skid resistance of concrete is measured at 5 minute intervals, until the concrete becomes completely iced. The anti-icing performance of 5 different fluids, both experimental and commercial, was assessed in comparison with a reference solution of 50% w/w K-formate. The anti-icing performance is analyzed based on two parameters: the duration (Icing Protection Time, IPT) and the effectiveness of this protection.
2015-06-15
Technical Paper
2015-01-2095
Wolfgang Hassler, Reinhard F.A. Puffing, Andreas Tramposch
Abstract This paper deals with thermal ice protection of electrically heated restraining grids designed for applications in the environmental control system (ECS) of passenger aircraft. The restraining grids described in the paper consist of strung, electrically insulated wire and are - in certain operation modes of the ECS - exposed to an airstream containing supercooled water droplets and/or ice particles. Heat is generated in the wire by an electric current, and the temperature of the wire is controlled with the aid of an electronic control system. A substantial question for laying out the controller and for operating the grids is the following: What minimum heating power is required to prevent ice accretion on the surface of the wire, i.e., what is the least heating power that is necessary to keep a grid being exposed to specific icing conditions devoid of ice? This problem is studied for a simple model system first and is then examined for restraining grids.
2015-06-15
Technical Paper
2015-01-2094
William B. Wright, Peter Struk, Tadas Bartkus, Gene Addy
Abstract This paper will describe two recent modifications to the LEWICE software. The version described is under development and not ready for release. First, a capability for modeling ice crystals and mixed phase icing has been modified based on recent experimental data. Modifications have been made to the ice particle bouncing and erosion model. This capability has been added as part of a larger effort to model ice crystal ingestion in aircraft engines. Comparisons have been made to ice crystal ice accretions performed in the NRC Research Altitude Test Facility (RATFac). Second, modifications were made to the runback model based on data and observations from thermal scaling tests performed in the NRC Altitude Icing Tunnel. The runback model was modified to match film models used in the open literature. An empirical water shedding was also implemented. Comparisons were made to thermal deicing data taken at the NRC Altitude Icing Tunnel.
2015-06-15
Technical Paper
2015-01-2097
Timothy A. Shannon, Stephen T. McClain
Abstract Changes in convection coefficient caused by the changes in surface roughness characteristics along an iced NACA 0012 airfoil were investigated in the 61-cm by 61-cm (24 in. by 24 in.) Baylor Subsonic Wind Tunnel using a 91.4-cm (36-in.) long heated aerodynamic test plate and infrared thermometry. A foam insert was constructed and installed on the wind tunnel ceiling to create flow acceleration along the test plate replicating the scaled flow acceleration the along the leading 17.1% (3.6 in.) of a 53.3-cm (21-in.) NACA 0012 airfoil. Two sets of rough surface panels were constructed for the study, and each surface used the same basic random droplet pattern created using the Lagrangian droplet simulator of Tecson and McClain (2013). For the first surface, the roughness pattern was replicated with the same geometry over the plate following a smooth-to-rough transition location noted in historical literature for the case being replicated.
2015-06-15
Technical Paper
2015-01-2096
Philippe Reulet, Bertrand Aupoix, David Donjat, Francis Micheli
Abstract Numerical simulation of ice accretion on aircraft surfaces necessitates a good prediction of wall friction coefficient and wall heat transfer coefficient. After the icing process begins, surface roughness induces a high increase of friction and heat transfer, but simple Reynolds analogy is no longer valid. An experimental campaign is conducted to provide a database for numerical model development in the simple configuration of a heated flat plate under turbulent cold airflow conditions. The flat plate model is placed in the centre of the test section of a wind tunnel. The test model is designed according to constraints for the identification of friction and heat transfer coefficients. It includes three identical resin plates which are moulded to obtain a specified roughness on the upper surface exposed to the flow. Only the 3rd resin plate is heated on its lower face by an electrical heater connected to a temperature regulator.
2015-06-15
Technical Paper
2015-01-2099
Mario Vargas, Charles Ruggeri, Peter Struk, Mike Pereira, Duane Revilock, Richard Kreeger
This work presents the results of an experimental study of ice particle impacts on a flat plate made of glass. The experiment was conducted at the Ballistics Impact Laboratory of NASA Glenn Research Center in 2014 and is part of the NASA fundamental research efforts to study physics of ice particles impact on a surface, in order to improve understanding of ice crystal ingestion and ice accretion inside jet engines. The ice particles, which were nominally spherical ranging in initial diameter between 1 and 3.5 millimeters, were accelerated to velocities from 20 to 130 m/s using a pressure gun. High speed cameras captured the pre-impact particle diameter and velocity data as well as the post-impact fragment data. The initial stages of ice particle breakup were captured and studied at 1,000,000 frames per second with a high speed camera imaging at a plane normal to the impact surface.
2015-06-15
Technical Paper
2015-01-2098
Stephen T. McClain, Mario Vargas, Richard E. Kreeger, Jenching Tsao
Abstract Many studies have been performed to quantify the formation and evolution of roughness on ice shapes created in Appendix C icing conditions, which exhibits supercooled liquid droplets ranging from 1-50 µm. For example Anderson and Shin (1997), Anderson et al. (1998), and Shin (1994) represent early studies of ice roughness during short-duration icing events measured in the Icing Research Tunnel at the NASA Glenn Research Center. In the historical literature, image analysis techniques were employed to characterize the roughness. Using multiple images of the roughness elements, these studies of roughness focused on extracting parametric representations of ice roughness elements. While the image analysis approach enabled many insights into icing physics, recent improvements in laser scanning approaches have revolutionized the process of ice accretion shape characterization.
2015-06-15
Technical Paper
2015-01-2084
Benedikt König, Ehab Fares, Andy P. Broeren
Abstract A Lattice-Boltzmann approach is used to simulate the aerodynamics of complex three-dimensional ice shapes on a NACA 23012 airfoil. The digitally produced high fidelity geometrical ice shapes were created using a novel laser scanning technique in the NASA Icing Research Tunnel. The geometrically fully resolved unsteady simulations are conducted on two ice shapes representing a roughness type and a horn type icing on the leading edge of the airfoil. Comparisons between simulation and experiment of lift, drag, and pitching moment as well as pressure distributions indicate overall a good qualitative agreement in capturing the aerodynamic degradation. Especially for the horn-type ice shape, the quantitative agreement is also mostly very good. Analysis of the flow structures indicates furthermore a good capturing of the three-dimensional separation behavior of the flow.
2015-06-15
Technical Paper
2015-01-2100
Yongsheng Lian, Yisen Guo
Abstract In this paper we numerically investigated the impact of large droplets on smooth solid surfaces to understand the splashing mechanism involved in ice accretion due to supercooled large droplets. A Navier-Stokes solver was used to describe the flow field, the moment-of-fluid (MOF) method was used to capture the droplet interface evolution, and the adaptive mesh refinement technique was employed to refine the mesh near the region of interest. We investigated the effect of air on splashing mechanism and confirmed that a low pressure can suppress the droplet splashing. The size distribution of splashed secondary droplets was studied and showed good agreement with experimental results. The effect of surface curvature on the splashing phenomenon was highlighted. Finally, the droplet impact on a NACA 23012 airfoil was studied and the water collection efficiency was investigated.
2015-06-15
Technical Paper
2015-01-2087
Delphine Leroy, Emmanuel Fontaine, Alfons Schwarzenboeck, J. Walter Strapp, Lyle Lilie, Julien Delanoe, Alain Protat, Fabien Dezitter, Alice Grandin
Abstract Despite past research programs focusing on tropical convection, the explicit studies of high ice water content (IWC) regions in Mesoscale Convective Systems (MCS) are rare, although high IWC conditions are potentially encountered by commercial aircraft during multiple in-service engine powerloss and airdata probe events. To gather quantitative data in high IWC regions, a multi-year international HAIC/HIWC (High Altitude Ice Crystals / High Ice Water Content) field project has been designed including a first field campaign conducted out of Darwin (Australia) in 2014. The airborne instrumentation included a new reference bulk water content measurement probe and optical array probes (OAP) recording 2D images of encountered ice crystals. The study herein focuses on ice crystal size properties in high IWC regions, analyzing in detail the 2D image data from the particle measuring probes.
2015-06-15
Technical Paper
2015-01-2091
Ryosuke Hayashi, Makoto Yamamoto
Abstract In a jet engine, ice accreted on a fan rotor can be shed from the blade surface due to centrifugal force, and the shed ice can damage compressor components. This phenomenon, which is referred to as ice shedding, threatens safe flight. However, there have been few studies on ice shedding because ice has numerous unknown physical parameters. Although existing icing models can simulate ice growth, these models do not have the capability to reproduce ice shedding. As such, in a previous study, we developed an icing model that takes into account both ice growth and ice shedding. In the present study, we apply the proposed icing model to a jet engine fan in order to investigate the effect of ice growth and shedding on the flow field. The computational targets of the present study are the engine fan and the fan exit guide vane (FEGV); thus, we simultaneously deal with the rotor-stator interaction problem.
2015-06-15
Technical Paper
2015-01-2088
Richard E. Kreeger, Lakshmi Sankar, Robert Narducci, Robert Kunz
Abstract The formation of ice over lifting surfaces can affect aerodynamic performance. In the case of helicopters, this loss in lift and the increase in sectional drag forces will have a dramatic effect on vehicle performance. The ability to predict ice accumulation and the resulting degradation in rotor performance is essential to determine the limitations of rotorcraft in icing encounters. The consequences of underestimating performance degradation can be serious and so it is important to produce accurate predictions, particularly for severe icing conditions. The simulation of rotorcraft ice accretion is a challenging multidisciplinary problem that until recently has lagged in development over its counterparts in the fixed wing community. But now, several approaches for the robust coupling of a computational fluid dynamics code, a rotorcraft structural dynamics code and an ice accretion code have been demonstrated.
2015-06-15
Technical Paper
2015-01-2093
Maxime Henno
Abstract Advanced sizing of the thermal wing ice protection system (WIPS) requires an improved and a robust manner to simulate the system operation in unsteady phases and particularly in de-icing operations. A two dimensional numerical tool has been developed to enable the simulation of unsteady anti-icing and de-icing operations. For example, the WIPS may be activated with delay after entering into the icing conditions. In this case, ice starts to accrete on the leading edge before the WIPS heats up the skin. Another example is the ground activation of the WIPS for several seconds to check its functionality: low external cooling may cause high thermal constraints that must be estimated with accuracy to avoid adverse effects on the structure. Thermal de-icing WIPS integrated in composite structures intrinsically have unsteady behaviors; the tool enables the computation of the skin temperature evolution with the time.
2015-06-15
Technical Paper
2015-01-2092
David M. Orchard, Catherine Clark, Myron Oleskiw
Abstract Simulations of supercooled large droplet (SLD) icing environments within the NRC's Altitude Icing Wind Tunnel (AIWT) have been performed in which broad band mass distribution spectra are achieved that include a distinct pattern of liquid water content (LWC) over a range of droplet sizes (i.e., bi-modal distribution). The mass distribution is achieved through modification of the existing spray system of the AIWT to allow two spray profiles with differing LWC and median volumetric diameter (MVD) to be simultaneously injected into the flow. Results of spray profile distributions measured in the test section have demonstrated that freezing drizzle conditions, where MVD is either less than or greater than 40 μm, can be achieved.
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