The impact of hybridization, engine combustion method, and energy management system connectivity on heavy-duty vehicle operation

2021 ◽  
pp. 095440702098304
Author(s):  
Carrie M Hall
Keyword(s):  
Real Time ◽  
Energy Management ◽  
High Efficiency ◽  
Fuel Efficiency ◽  
Vehicle Speed ◽  
Heavy Duty ◽  
Wide Range ◽  
Engine Combustion ◽  
The Impact ◽  
Heavy Duty Vehicles

A wide range of strategies for reducing energy consumption from heavy-duty vehicles have been explored from vehicle electrification to real-time vehicle energy management based on vehicle-to-vehicle and vehicle-to-infrastructure communication. Full electrification of heavy-duty vehicles can be challenging due to current limitations on battery energy density. However, hybridization and the implementation of high efficiency engines present other potential near-term solutions. In contrast to many prior studies that have explored the use of one or two of these techniques, this work discusses the combined influence of hybridization level, engine combustion mode, and connected energy management on fuel efficiency in heavy-duty applications. The impact of hybridization in different driving conditions is quantified and the effectiveness of hybrid powertrain structures with different engine combustion strategies is also explored. Utilizing an alternative combustion strategy can improve fuel efficiency by 5% in conventional and mild hybrids but was found to have a more minimal impact in full hybrids. An additional layer of complexity is also introduced when vehicles have some degree of connectivity and this influence on the energy management method is investigated by comparing control approaches which leverage current and future vehicle speed information. Connectivity and the ability to optimize energy production in real-time was found to be essential in uncertain cases and enable improvements in fuel consumption of up to 12% over baseline cases.

An Experimental and Numerical Study of a Hydrogen Fueled, Directly Injected, Heavy Duty Engine at Knock-Limited Conditions

2020 ◽  
Author(s):  
Joel Mortimer ◽  
Stephen Yoannidis ◽  
Farzad Poursadegh ◽  
Zhewen Lu ◽  
Michael Brear ◽  
...  
Keyword(s):  
High Efficiency ◽  
Numerical Study ◽  
Engine Performance ◽  
Cylinder Pressure ◽  
Heavy Duty ◽  
Ignition Timing ◽  
High Compression Ratio ◽  
Combustion Modeling ◽  
Wide Range ◽  
The Impact

Abstract This paper presents an experimental and numerical study of a directly injected, spark-ignited (DI SI), heavy duty hydrogen fueled engine at knock-limited conditions. The impact of air-fuel ratio and ignition timing on engine performance is first investigated experimentally. Two-zone combustion modeling of the hydrogen fueled cylinder is then used to infer burn profiles and unburned, end-gas conditions using the measured in-cylinder pressure traces. Simulation of the autoignition chemistry in this end-gas is then undertaken to identify key parameters that are likely to impact knock-limited behavior. The experiments demonstrate knock-limited performance on this high compression ratio engine over a wide range of air-fuel ratios, λ. Other trends with λ are qualitatively similar to those shown in previous studies of hydrogen fueled engines. Kinetic simulations then suggest that some plausible combination of residual nitric oxide from previous cycles and locally high charge temperatures at intake valve closing can lead to autoignition at the knock-limited conditions identified in the experiments. This prompts a parametric study that shows how increased λ makes hydrogen less likely to autoignite, and suggests options for the design of high efficiency, directly injected, hydrogen fueled engines.

Account of Film Turbulence for Predicting Film Cooling Effectiveness in Gas Turbine Combustors

1979 ◽  
Author(s):  
G. J. Sturgess
Keyword(s):  
Gas Turbine ◽  
Film Cooling ◽  
Cooling Effectiveness ◽  
Turbine Engine ◽  
Film Cooling Effectiveness ◽  
Wide Range ◽  
Engine Combustion ◽  
Turbulence Effects ◽  
The Impact ◽  
Combustor Liner

The paper deals with a small but important part of the overall gas turbine engine combustion system and continues earlier published work on turbulence effects in film cooling to cover the case of film turbulence. Film cooling of the gas turbine combustor liner imposes certain geometric limitations on the coolant injection device. The impact of practical film injection geometry on the cooling is one of increased rates of film decay when compared to the performance from idealized injection geometries at similar injection conditions. It is important to combustor durability and life estimation to be able to predict accurately the performance obtainable from a given practical slot. The coolant film is modeled as three distinct regions, and the effects of injection slot geometry on the development of each region are described in terms of film turbulence intensity and initial circumferential non-uniformity of the injected coolant. The concept of the well-designed slot is introduced and film effectiveness is shown to be dependent on it. Only slots which can be described as well-designed are of interest in practical equipment design. A prediction procedure is provided for well-designed slots which describes growth of the film downstream of the first of the three film regions. Comparisons of predictions with measured data are made for several very different well-designed slots over a relatively wide range of injection conditions, and good agreement is shown.

scholarly journals An Adaptive Bitrate Switching Algorithm for Speech Applications in Context of WebRTC

2021 ◽  
Vol 17 (4) ◽  
pp. 1-21
Author(s):  
Mohannad Alahmadi ◽  
Peter Pocta ◽  
Hugh Melvin
Keyword(s):  
Real Time ◽  
Data Exchange ◽  
Quality Of Experience ◽  
End User ◽  
High Quality ◽  
Content Type ◽  
Switching Algorithm ◽  
Wide Range ◽  
The Impact

Web Real-Time Communication (WebRTC) combines a set of standards and technologies to enable high-quality audio, video, and auxiliary data exchange in web browsers and mobile applications. It enables peer-to-peer multimedia sessions over IP networks without the need for additional plugins. The Opus codec, which is deployed as the default audio codec for speech and music streaming in WebRTC, supports a wide range of bitrates. This range of bitrates covers narrowband, wideband, and super-wideband up to fullband bandwidths. Users of IP-based telephony always demand high-quality audio. In addition to users’ expectation, their emotional state, content type, and many other psychological factors; network quality of service; and distortions introduced at the end terminals could determine their quality of experience. To measure the quality experienced by the end user for voice transmission service, the E-model standardized in the ITU-T Rec. G.107 (a narrowband version), ITU-T Rec. G.107.1 (a wideband version), and the most recent ITU-T Rec. G.107.2 extension for the super-wideband E-model can be used. In this work, we present a quality of experience model built on the E-model to measure the impact of coding and packet loss to assess the quality perceived by the end user in WebRTC speech applications. Based on the computed Mean Opinion Score, a real-time adaptive codec parameter switching mechanism is used to switch to the most optimum codec bitrate under the present network conditions. We present the evaluation results to show the effectiveness of the proposed approach when compared with the default codec configuration in WebRTC.

scholarly journals An Overview of Heavy Trucks/Buses Braking Performance

1991 ◽  
Vol 8 (1) ◽  
Author(s):  
Richard M. Ziernicki
Keyword(s):  
Statistical Data ◽  
Vehicle Speed ◽  
Test Results ◽  
Heavy Duty ◽  
Braking Performance ◽  
Emergency Braking ◽  
Heavy Trucks ◽  
Brake Performance ◽  
Drag Factor ◽  
Heavy Duty Vehicles

The writer discusses the performance of heavy duty vehicles during emergency braking. The paper reviews statistical data related to the trucking accidents, and discusses brake performance, tires, and the stopping ability of heavy duty vehicles. Relationships between drag factor, coefficient of friction, vehicle speed, type of tire, road surface, brake design, and brake temperature are discussed. Some of the test results performed on heavy trucks are presented. The discussion is general in order to make the presentation useful both to practicing reconstruction specialists, and to attorneys.

scholarly journals Impact of Transformer Turns Ratio on the Power Losses and Efficiency of the Wide Range Isolated Buck–Boost Converter for Photovoltaic Applications

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5645
Author(s):  
Hamed Mashinchi Maheri ◽  
Dmitri Vinnikov ◽  
Andrii Chub ◽  
Vadim Sidorov ◽  
Elizaveta Liivik
Keyword(s):  
High Efficiency ◽  
Input Voltage ◽  
Power Losses ◽  
Efficient Operation ◽  
Wide Range ◽  
Photovoltaic Applications ◽  
Theoretical Predictions ◽  
Converter Topology ◽  
Isolation Transformer ◽  
The Impact

In this paper, the impact of transformer turns ratio on the performance of the quasi-Z-source galvanically isolated DC-DC converters is studied. Embedded buck–boost functionality enables these converters to regulate the input voltage and load in a wide range, which makes them suitable for such demanding application as photovoltaic microconverters. The isolation transformer here plays a central role as its turns ratio defines the point of transition between the boost and buck modes and overall capability of the converter to regulate the input voltage in a wide range at high efficiency. The studied quasi-Z-source galvanically isolated DC-DC converter is benchmarked in terms of power loss of components and weighted power conversion efficiency for three different turns ratios of isolation transformer to achieve the best and optimized turns ratio lead to the efficient operation. Operation in a wide range of input voltage at high efficiency is the main criterion for assessing the effect of turns ratio on the efficiency of the converter. The proposed loss model and theoretical predictions of the efficiency were validated with the help of a 300 W experimental prototype of the photovoltaic microconverter based on the quasi-Z-source galvanically isolated DC-DC converter topology.

Account of Film Turbulence for Predicting Film Cooling Effectiveness in Gas Turbine Combustors

1980 ◽  
Vol 102 (3) ◽  
pp. 524-534 ◽  
Author(s):  
G. J. Sturgess
Keyword(s):  
Gas Turbine ◽  
Film Cooling ◽  
Cooling Effectiveness ◽  
Turbine Engine ◽  
Film Cooling Effectiveness ◽  
Wide Range ◽  
Engine Combustion ◽  
Turbulence Effects ◽  
The Impact ◽  
Combustor Liner

The paper deals with a small but important part of the overall gas turbine engine combustion system and continues earlier published work on turbulence effects in film cooling to cover the case of film turbulence. Film cooling of the gas turbine combustor liner imposes certain geometric limitations on the coolant injection device. The impact of practical film injection geometry on the cooling is one of increased rates of film decay when compared to the performance from idealized injection geometries at similar injection conditions. It is important to combustor durability and life estimation to be able to predict accurately the performance obtainable from a given practical slot. The coolant film is modeled as three distinct regions, and the effects of injection slot geometry on the development of each region are described in terms of film turbulence intensity and initial circumferential non-uniformity of the injected coolant. The concept of the well-designed slot is introduced and film effectiveness is shown to be dependent on it. Only slots which can be described as well-designed are of interest in practical equipment design. A prediction procedure is provided for well-designed slots which describes growth of the film downstream of the first of the three film regions. Comparisons of predictions with measured data are made for several very different well-designed slots over a relatively wide range of injection conditions, and good agreement is shown.

Telecardiology and its settings of application: An update

2017 ◽  
Vol 24 (5) ◽  
pp. 373-381 ◽  
Author(s):  
Giuseppe Molinari ◽  
Martina Molinari ◽  
Matteo Di Biase ◽  
Natale D Brunetti
Keyword(s):  
Real Time ◽  
Tertiary Care ◽  
Implantable Devices ◽  
Decision Making Process ◽  
Clinical Settings ◽  
Medical Specialties ◽  
Coronary Syndrome ◽  
Wide Range ◽  
Patients With Heart Failure ◽  
The Impact

Among the wide range of medical specialties in which telemedicine has been successfully applied, cardiology can be considered as one of the most important fields of application. Through the transmission of clinical data and the electrocardiogram, telecardiology allows access to a real-time assessment (teleconsultation) without any need to travel for both patient and cardiologist. This review discusses the impact of telecardiology in different clinical settings of application. Pre-hospital telecardiology has proved to be useful either in the clinical management of remote patients with acute coronary syndrome or in supporting the decision-making process of general practitioners. In the setting of in-hospital telecardiology, most of the applications refer to real-time echocardiography transmissions between rural small hospitals and tertiary care centres, particularly for the diagnosis or exclusion of congenital heart disease in newborns. Finally, many trials show that post-hospital telecardiology improves outcomes and reduces re-admissions or outpatient contacts in patients with heart failure, arrhythmias or implantable devices.

scholarly journals A Prototype of a Robot Capable of Tracking Anyone with a High Body Temperature in Crowded Areas

2021 ◽  
Vol 17 (11) ◽  
pp. 103
Author(s):  
Mohamed Zied Chaari ◽  
Abdulaziz Aljaberi
Keyword(s):  
Body Temperature ◽  
Real Time ◽  
High Efficiency ◽  
Thermal Camera ◽  
Public Places ◽  
Health Crisis ◽  
Service Demand ◽  
Mechanical Parts ◽  
Real Time Measurement ◽  
The Impact

<p>People's health and the world economy around worldwide are under the impact of the virus. Controlling the propagation of coronavirus is extraordinarily challenging after the seventeen months since the pandemic outbreak. This research will represent the efficiency of robots in helping humanity in facing the Corona pandemic and the global health crisis. According to the quick and widespread Covid-19 contagion globally, healthcare service demand increased staff with less availability. In this crisis, robotics is the safe solution at a low price to support people to fight Covid-19.</p><p>Furthermore, it is essential to relax lockdown restrictions after the increase in the number of people vaccinated. In this context, we designed a mobile robot with a thermal temperature scanner for pedestrians and identified those with abnormal temperatures over 39°C in public places and track them in real time. This robot features a long-lasting, lightweight battery and a high-quality thermal camera. Our primary target is to reduce the risk of transmission between people.  We use a single-board computer and a thermal camera to detect unusual fevers near real-time to achieve this design and prototyping. In addition, we use image processing to detect target pedestrians and a control system to guide the robot. This robot can bypass any potential obstacles that can prevent it from moving around and cause problems. The development of this robot mainly focuses on the real-time measurement of body temperature at a distance of two meters. The compensation algorithm can coordinate between the mechanical parts of the robot and high-efficiency design.</p>

Locomotive Crash Energy Management Vehicle-to-Vehicle Impact Test Results

2020 ◽  
Author(s):  
Patricia Llana ◽  
Karina Jacobsen ◽  
Richard Stringfellow
Keyword(s):  
Energy Management ◽  
Research Program ◽  
Impact Test ◽  
Test Model ◽  
Test Results ◽  
Vehicle To Vehicle ◽  
Vehicle Collision ◽  
Vehicle Impact ◽  
Wide Range ◽  
The Impact

Abstract Research to develop new technologies for increasing the safety of passengers and crew in rail equipment is being directed by the Federal Railroad Administration’s (FRA’s) Office of Research, Development, and Technology. Two crash energy management (CEM) components that can be integrated into the end structure of a locomotive have been developed: a push-back coupler (PBC) and a deformable anti-climber (DAC). These components are designed to inhibit override in the event of a collision. The results of vehicle-to-vehicle override, where the strong underframe of one vehicle, typically a locomotive, impacts the weaker superstructure of the other vehicle, can be devastating and compromise the occupied space. The objective of this research program is to demonstrate the feasibility of these components in improving crashworthiness for equipped locomotives in a wide range of potential collisions, including collisions with conventional locomotives, conventional cab cars, and freight equipment. Concerns have been raised in discussions with industry that push-back couplers may trigger prematurely, or may require replacement due to unintentional activation as a result of loads experienced during service and coupling. PBCs are designed with trigger loads which exceed the expected maximum service and coupling loads experienced by conventional couplers. Analytical models are typically used to determine these trigger loads. Two sets of coupling tests have been conducted that validate these models, one with a conventional locomotive equipped with conventional draft gear and coupler, and another with a conventional locomotive retrofit with a PBC. These tests provide a basis for comparing the coupling performance of a CEM-equipped locomotive with that of a conventional locomotive, as well as confirmation that the PBC triggers at a speed well above typical coupling speeds and at the designed force level. In addition to the two sets of coupling tests, two vehicle-to-vehicle collision tests where one of the vehicles is a CEM-equipped locomotive and a train-to-train collision test are planned. This arrangement of tests allows for evaluation of CEM-equipped locomotive performance, and enables comparison of actual collision behavior with predictions from computer models in a range of collision scenarios. This paper describes the results of the most recent test in the research program: the first vehicle-to-vehicle impact test. In this test, a CEM-equipped locomotive impacted a stationary conventional locomotive. The primary objective of the test was to demonstrate the effectiveness of the components of the CEM system in working together to absorb impact energy and to prevent override in a vehicle-to-vehicle collision scenario. The target impact speed was 21 mph. The actual speed of the test was 19.3 mph. Despite the lower test speed, the CEM system worked exactly as designed, successfully absorbing energy and keeping the vehicles in-line, with no derailment and no signs of override. The damage sustained during the collision is described. Prior to the tests, a finite element model was developed to predict the behavior of the CEM components and test vehicles during the impact. The test results are compared to pre-test model predictions. The model was updated with the conditions from the test, resulting in good agreement between the updated model and the test results. Plans for future full-scale collision tests are discussed.

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