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Technical Paper

Windtunnel Catalyticity Evaluation for Thermoprotective Elements

22 Flexible External Insulation (FEI) Blankets of various types were subjected to a plasma aging in simulated reentry conditions in TsAGI’s VAT-104 windtunnel in the frame of 4 test campaigns on FEI characterization. Blankets were tested at top side temperature Tw =800…1200°C during 60 min each. Widespread numerical simulation of the test conditions and the model heating was performed using full Navier-Stokes equations. FEI catalyticity obtained from correlation between measured and calculated heat fluxes is Kw=1…10m/s.
Technical Paper

Winterization of Vehicles To -50F

Discussion in this paper is centered on general problems of subarctic operation, results of the 1968-1969 winter testing at Ft. Churchill, Manitoba, Canada, and the testing planned for the 1969-1970 season at Ft. Churchill. Significant findings from the 1968-969 testing indicate the vital importance of care in preparation of vehicles for the arctic, the need for greater simplicity and reliability in design of winterization systems, and the inadequacy of currently used elastomeric components (hoses, o-rings, etc.).
Technical Paper

Wiper Systems With Flexible Structures - Instabilities Analysis and Correlation with a Theoretical Model

Optimizing the wiper system performance motivates the design engineer to create a product as robust as possible against the occurrence of wipe defects related to vibratory phenomena between the rubber blade and the windshield. In some configurations, these vibrations generate visual or audible annoyance for the driver. These instabilities phenomena only appear under specific operating and environmental conditions characterized by windshield moisture and cleanness, contact pressure of the rubber blade on the glass, attack angle of the wiper blade on the windshield, component stiffness, windshield curvature etc. In the process of eliminating all potential instabilities, modeling the wiper system structures can contribute to understand its working dynamics. Therefore, a new computation tool is developed and validated by experimentation on a specific test bench.
Technical Paper

Wire Braid Angle Response Characteristics in Hydraulic Hose

This report is concerned with the effects of braid angle on the behavior of hydraulic hose. For equilibrium conditions to exist, and if the braid layers are assumed to bear tension forces only, the angle of the reinforcement layers must be along that of the total force exerted by the internal pressure. This is the neutral angle θN, which has a theoretical value of 54.74° (54°44′). It is possible to hypothesize a fretting wear model in which wires move on top of one another inside a braid layer if the braid angle is different from this theoretical neutral angle. Even though theoretical claims are made by some technical professionals, the hydraulic hose industry has been successfully making hoses with non-neutral braid angles for years. Testing and application have shown that fretting wear is not a principal cause of hose failure and fatigue.
Technical Paper

Wire Harness Simulation and Analysis Techniques

An increasingly important, yet often underestimated task of modern vehicle design is the system interconnect, commonly known as the wire harness. The continual increase in on–board vehicle electronics is causing an exponential expansion in wire harness complexity. To meet these challenges, software tools have been developed to assist the harness designer in the various tasks from system partitioning to signal integrity analysis. This paper will discuss the key problem areas of the wire harness design, along with the design and analysis capabilities of the SaberHarness™ tool suite.
Technical Paper

Wire Segment Error Locating Algorithm for Wiring Connection Verification Tool

Due to increasing amount of modules and customized options in commercial vehicles, it becomes more and more difficult to verify the circuit design. In this paper, a wire segment error locating algorithm is proposed to automate the exact wire segment error locating process. When a wrong connection is found by existing tool, guided by the exact description of wire segment error, this algorithm can locate exact wire segment error in the connection by searching for the one that has at least one neighboring segment from a correct connection.
Technical Paper

Wireless Charging for EV/HEV with Prescriptive Analytics, Machine Learning, Cybersecurity and Blockchain Technology: Ongoing and Future Trends

Due to the rapid development in the technological aspect of the autonomous vehicle (AV), there is a compelling need for research in the field vehicle efficiency and emission reduction without affecting the performance, safety and reliability of the vehicle. Electric vehicle (EV) with rechargeable battery has been proved to be a practical solution for the above problem. In order to utilize the maximum capacity of the battery, a proper power management and control mechanism need to be developed such that it does not affect the performance, reliability and safety of vehicle. Different optimization techniques along with deterministic dynamic programming (DDP) approach are used for the power distribution and management control. The battery-operated electric vehicle can be recharged either by plug-in a wired connection or by the inductive mean (i.e. wirelessly) with the help of the electromagnetic field energy.

Wireless Power Transfer for Heavy-Duty Electric Vehicles

The published SAE J2954 standard established an industry-wide specification that defines acceptable criteria for interoperability, electromagnetic compatibility, EMF, minimum performance, safety, and testing for wireless power transfer (WPT) for light-duty plug-in electric vehicles. This SAE Information Report, SAE J2954/2, defines new power transfer levels in the higher power ranges needed for heavy-duty electric vehicles. This document addresses the requirements based on these charge levels and different vehicle applications as a first step in the process of completing a standard that the industry can use, both for private (fleet) and public wireless power transfer, including for charging electric vehicle batteries. This document is the first step in a process towards HD static and dynamic WPT. This document lacks specific requirements and solutions, for which field data is needed.

Wiring Aerospace Vehicle

This specification covers all aspects from the selection through installation of wiring and wiring devices and optical cabling and termination devices used in aerospace vehicles. Aerospace vehicles include manned and unmanned airplanes, helicopters, lighter-than- air vehicles, missiles and external pods.

Wiring Aerospace Vehicle

This specification covers all aspects from the selection through installation of wiring and wiring devices and optical cabling and termination devices used in aerospace vehicles. Aerospace vehicles include manned and unmanned airplanes, helicopters, lighter-than- air vehicles, missiles and external pods.
Technical Paper

Wissler Simulations of a Liquid Cooled and Ventilation Garment (LCVG) for Extravehicular Activity (EVA)

In order to provide effective cooling for astronauts during extravehicular activities (EVAs), a liquid cooling and ventilation garment (LCVG) is used to remove heat by a series of tubes through which cooling water is circulated. To better predict the effectiveness of the LCVG and determine possible modifications to improve performance, computer simulations dealing with the interaction of the cooling garment with the human body have been run using the Wissler Human Thermal Model. Simulations have been conducted to predict the heat removal rate for various liquid cooled garment configurations. The current LCVG uses 48 cooling tubes woven into a fabric with cooling water flowing through the tubes. The purpose of the current project is to decrease the overall weight of the LCVG system. In order to achieve this weight reduction, advances in the garment heat removal rates need to be obtained.
Technical Paper

Wooden Pole Fracture Energy in Vehicle Impacts

Impacts with trees and wooden utility poles represent a significant subset of vehicular collisions. For example, while fixed object collisions account for less than 8% of all crashes, they represent nearly 30% of all fatal crashes. Also, nearly half (over 43%) of all fixed-object impacts are into a tree, pole, or post. This paper is viewed as a first attempt to understand the energy absorbing processes operating when vehicles strike trees and wooden poles in order to make reasonable estimates of the magnitude of the tree/pole energy dissipated in the crash. This initial study is comprised of a literature review, a series of scale model pole/pendulum impacts, and an analytical study which is comprised of both a static analysis and a dynamic finite element model (FEM) analysis of a vehicle/pole impact. As a result of this work, a methodology has been evolved for making estimates of tree/pole energy.
Technical Paper

Work Extraction Efficiency in a Series Hybrid Opposed Piston Engine

This work investigates the development of a novel series hybrid architecture utilizing a single cylinder opposed piston engine. The opposed piston engine presents unique benefits in a hybrid architecture such as its lower heat transfer due to a favorable surface area to volume ratio and lack of a cylinder head, as well as the thermodynamic benefits of two stroke operation with uniflow scavenging. A particular focus of this effort is the work extraction efficiency of two design concepts. The first design concept utilizes a geartrain to couple the crankshafts of the engine in a conventional manner, providing a single power take-off for coupling to an electric motor/generator. In this design, the large inertia of the geartrain dampens the speed fluctuation of the single cylinder engine, reducing the peak torque required to for the electric machine. However, the friction losses caused by the geartrain limit the maximum work extraction efficiency.
Technical Paper

Work-Energy Relationships for the Collinear Single Degree of Freedom Impact Model under the Case of Net Unbalanced Externally Applied Forces

Externally applied unbalanced forces and their corresponding impulses are generally excluded from consideration in regards to the evaluation of the collision phase events for a system comprised of two motor vehicles undergoing collinear impact. This exclusion is generally warranted secondary to the fact that the collision force and its corresponding impulse are dominant during the collision phase. Conceptually, two exclusions exist to this approach. The first is the situation in which significant physical restraints are present to the displacement of one or both collision partners and are of sufficient magnitude as to require inclusion. Generally, this represents the exceptional case and includes, but is not limited to, situations in which one vehicle is snagged, in a non-eccentric manner, by a rigid narrow-width object such as a pole or other similar restraint, prior to the occurrence of the subsequent vehicle-to-vehicle collision under evaluation.

Workflow Modeling: Tools for Process Improvement and Application Development, Second Edition

This extensively revised second edition of the acclaimed and bestselling book, Workflow Modeling serves as a complete guide to discovering, scoping, assessing, modeling, and redesigning business processes. Taking into account the feedback from clients, workshop students, business professionals and other readers of the first edition, the authors have created this thoroughly updated and expanded resource, offering you clear, current, and concise guidance on creating highly effective workflow systems for your organization. Providing proven techniques for identifying, modeling, and redesigning business processes, and explaining how to implement workflow improvement, this book helps you define requirements for systems development or systems acquisition. By showing you how to build visual models for illustrating workflow, the authors help you to assess your current business processes and see where process improvement and systems development can take place.
Technical Paper

Workforce Enterprise Modeling

Currently, many factors influence the NASA Kennedy Space Center (KSC) workforce. These factors include the drive for return to flight, a Shuttle Program end date of 2010, and the Vision for Space Exploration which calls for the development of a new launch vehicle. Additionally, external factors exist as well, such as the area's cost of living, the availability of skilled resources, and the unemployment rate affect the overall workforce climate. To manage the human capital in a manner consistent with safety and mission success, and to strategically position NASA KSC to execute its future mission, it is necessary to understand how all of these different influencing factors work together to produce an overall workforce climate. We have been using System Dynamics models in order to capture some of these factors. These system dynamics models are also the starting point of agent-based models.
Technical Paper

Working Activity in Space: Preparation of the Scientific Experiments' Performance

One of the most unsolved problems in space projects, where human beings are involved, is the impossibility of simulating on the ground the effects of microgravity on astronauts' operability in space. [1] In particular, this is traceable in the performance of work activities, such as performing physiological scientific experiments. [2] This paper focuses on a study of the gap between the two operational scenarios: the ground test simulation and the in-flight space performance of complex physiological experiments. The major differences between the two operational scenarios are highlighted, and recommendations for improvement are suggested. The main finding of this paper is that, in order to make experiment performance not only possible but also easy and efficient, it is necessary to consider all human factors involved. With this perspective, the author's aim has been to find an effective way to consider all human factors of the ground and space operational conditions.
Technical Paper

Working Fluid De-freezing in Radiator on Base of LHP

Selection of working fluid is one of the main criterions for designing of heat pipes thermal control systems (TCS) for space application. In this paper we will describe how we solved the task of development of the TCS with working fluid of high thermal physical properties. In 2004-2006 we developed the Engineering model of Deployable Radiator based on Loop Heat Pipe by CAST purchase order. It was developed for qualification tests. Ammonia application as LHP working fluid is stipulated by its high thermal physical properties. However Ammonia freezing temperature is of minus 77ºC. Such fact impedes Ammonia application when operation temperatures of LHP Radiator are lower than this value, for example, It takes several tens of hours to orbit a spacecraft and prepare it for work (at that moment the spacecraft is out of power supply) and the working fluid can be frozen in a condenser-radiator when the spacecraft being in the shadow over a long period of time.
Technical Paper

Working Fluid Properties Variation During Combustion in Premixed Charge Hydrogen Engines

Several studies have been performed to investigate the effects of using hydrogen in spark ignition (SI) engines. One general conclusion that emerged was that stoichiometric operation of premixed charge hydrogen engines features increased losses compared to other fuels such as methane. Most studies attribute this higher loss to increased rates of heat transfer from the working fluid to the combustion chamber walls. Indeed, heat flux measurements during combustion and expansion recorded much higher values for hydrogen compared to methane stoichiometric operation. With regard to fluid properties, using the same net heat release equation as for gasoline engines results in an over prediction of heat losses to the combustion chamber walls. Also, the variation of specific heats ratio greatly influences calculated values for the rate of heat release. Therefore, a more detailed analysis of heat losses is required when comparing hydrogen to other fuels.