Electrified hydraulic power steering system in hybrid electric heavy trucks

Over the last 20 years, conventional automotive engine ancillaries have migrated from being mechanically powered to electrically powered in order to meet market demand. To adopt this trend in heavy trucks requires a higher power electrical system in order to cope with the higher loads placed upon it. Until the advent of the hybrid electric heavy truck (HET) this power infrastructure has not been available. HET's require a higher voltage system in order to reduce losses and provide adequate power and voltage levels for the traction motor. This study investigates for the first time the benefit of electrifying a hydraulic power assisted steering system in an HET. The developed electrical hydraulic power steering (EHPS), using a high-voltage traction battery, is found to drastically reduce the consumed energy over a drive cycle by optimal operation of the pump over the driving cycle. Empirical data from a prototype HET with EHPS confirms the simulation results from Dymola

High step-up interleaved boost converter utilising stacked half-bridge rectifier configuration

This paper proposes a solution to complement the insufficient voltage gain and voltage stress distribution of classical interleaved boost converter in high step-up application. An interleaved converter integrating coupled inductor and voltage multiplier cell, which provides an additional voltage gain is proposed. By stacking the secondary side of the interleaved coupled inductor to its primary side, a high step-up voltage gain and distributed voltage stress are realised. Low-voltage rated devices ultimately reduce the conduction losses. The principle of operation and the performance characteristic of the converter are presented and verified by an experimental prototype of 140 W, 12 V input, and 120 V output

Load analysis of ground-powering systems for electric vehicles

Dynamic conductive road charging involves the transfer of power into moving Electric Vehicles (EVs) using sliding contacts. The power transfer mechanism can be either installed from the top of the car using overhead conductors, conducting rails installed along the road-side or ground-level systems embedded in the road surface. The ground-level power system is the preferred option as it minimizes aerodynamic resistance compared to the other two as well as being designed for operation with vehicles of various sizes. In addition, existing technologies used in trams can be modified to provide ground-level EV charging systems. This paper investigates a ground-level system for EVs driving at high-speed on a motorway. It is based on the Tracked Electric Vehicle (TEV) project where EVs drive autonomously in a platoon with short inter-vehicle distance to reduce the overall air drag coefficient of the platoon. The paper investigates the optimum length and distance for the ground-level system. A Simulink model is developed for platoons of 10 EVs powered from a converter. It is shown that, for a platoon of 10 EVs driving with an inter-platoon distance of 50 m, a conducting-bar section100 m in length is the most efficient in terms of load variation and voltage stability

Medium temperature heat pipes – Applications, challenges and future direction

Data availability: Additional data to those provided in the supplementary documents can be made available upon approval of sponsor company.Supplementary material is available online at https://www.sciencedirect.com/science/article/pii/S135943112301400X?via%3Dihub#s0130 .Copyright © 2023 The Authors. Heat pipes have played a large part in the thermal management market for the past five decades and have contributed to the development and optimisation of countless components in a wide range of high-level applications, most notably in the aerospace, electronics, automotive and power generation industries. These thermal management systems span a wide range of temperatures, which in turn requires the heat pipe fluid and casing material to be specially selected to meet the application requirements. Recently, there has been an increasing demand for heat pipes which can operate in the 300–600 °C temperature range – a range which is still underdeveloped in the heat pipe marketplace due to the lack of conventional fluids which can adequately operate at these temperatures. This range is referred to as the ‘medium’ or ‘intermediate’ temperature range. The analysis and exploration of novel fluids, which could potentially be used in this range, will cater for a huge market potential. Although there has been mild development in this temperature range with the aim of testing particular fluid/metal combinations which may be suitable, there appears to currently be a severe lack of continuity in the work with little progression towards a definitive solution and no central reference catalogue of successful and unsuccessful tests. Previous works on the topic tends to follow a ‘patchwork’ process, often with overlaps in testing and with a focus only on long-term compatibility tests with a limited analytical approach which often lead to incompatible results. This paper intends to summarise all major and stand out efforts in developing medium temperature heat pipes and highlight the most promising fluids and wall materials which have been tested to date. To summarise the content, this review will explore (a) current applications which could benefit from the use of medium temperature heat pipes, (b) the work that has been done on investigating medium temperature fluids, (c) highlight some of the principles behind heat pipe performance prediction, fluid analysis, fluid/metal compatibility and fluid selection and (d) suggest the potential future direction of research in this area, particularly focusing on the development of novel heat pipe fluids. Additionally, a standardised fluid assessment framework is also proposed aiming to aid the identification and analysis of both existing and newly developed heat pipe fluids.Engineering and Physical Sciences Research Council (project code 1790747); European H2020-MSCA-RISE ThermaSMART project (project code 778104); Boyd Technologies Ashington UK Ltd

Flavor decomposition of the sea quark helicity distributions in the nucleon from semi-inclusive deep-inelastic scattering

Double-spin asymmetries of semi-inclusive cross sections for the production of identified pions and kaons have been measured in deep-inelastic scattering of polarized positrons on a polarized deuterium target. Five helicity distributions including those for three sea quark flavors were extracted from these data together with re-analyzed previous data for identified pions from a hydrogen target. These distributions are consistent with zero for all three sea flavors. A recently predicted flavor asymmetry in the polarization of the light quark sea appears to be disfavored by the data.Comment: 5 pages, 3 figure

Nuclear Polarization of Molecular Hydrogen Recombined on a Non-metallic Surface

The nuclear polarization of $\mathrm{H}_2$ molecules formed by recombination of nuclear polarized H atoms on the surface of a storage cell initially coated with a silicon-based polymer has been measured by using the longitudinal double-spin asymmetry in deep-inelastic positron-proton scattering. The molecules are found to have a substantial nuclear polarization, which is evidence that initially polarized atoms retain their nuclear polarization when absorbed on this type of surfac

First Measurement of the Tensor Structure Function b1b_1 of the Deuteron

The \Hermes experiment has investigated the tensor spin structure of the deuteron using the 27.6 GeV/c positron beam of \Hera. The use of a tensor polarized deuteron gas target with only a negligible residual vector polarization enabled the first measurement of the tensor asymmetry \At and the tensor structure function \bd for average values of the Bj{\o}rken variable $0.01<0.45$ and of the squared four-momentum transfer $0.5 {\rm GeV^2} <5 {\rm GeV^2}$. The quantities \At and \bd are found to be non-zero. The rise of \bd for decreasing values of $x$ can be interpreted to originate from the same mechanism that leads to nuclear shadowing in unpolarized scattering

Search for an exotic S=-2, Q=-2 baryon resonance at a mass near 1862 MeV in quasi-real photoproduction

A search for an exotic baryon resonance with $S=-2, Q=-2$ has been performed in quasi-real photoproduction on a deuterium target through the decay channel $\Xi^- \pi^- \to \Lambda \pi^- \pi^- \to p \pi^- \pi^- \pi^-$. No evidence for a previously reported $\Xi^{--}(1860)$ resonance is found in the $\Xi^- \pi^-$invariant mass spectrum. An upper limit for the photoproduction cross section of 2.1 nb is found at the 90% confidence level. The photoproduction cross section for the $\Xi^{0}(1530)$ is found to be between 9 and 24 nb