Temperature (T) is probably the most fundamental parameter in all kinds of science. Respective sensors are widely used in daily life. Besides conventional thermometers, optical sensors are considered to be attractive alternatives for sensing and on-line monitoring of T. This Review article focuses on all kinds of luminescent probes and sensors for measurement of T, and summarizes the recent progress in their design and application formats. The introduction covers the importance of optical probes for T, the origin of their T-dependent spectra, and the various detection modes. This is followed by a survey on (a) molecular probes, (b) nanomaterials, and (c) bulk materials for sensing T. This section will be completed by a discussion of (d) polymeric matrices for immobilizing T-sensitive probes and (e) an overview of the various application formats of T-sensors. The review ends with a discussion on the prospects, challenges, and new directions in the design of optical T-sensitive probes and sensors.

Luminescent probes and sensors for temperature.

Progress and recent trends in homogeneous charge compression ignition (HCCI) engines

Review of high efficiency and clean reactivity controlled compression ignition (RCCI) combustion in internal combustion engines

Soot processes in compression ignition engines

A fuel reactivity controlled compression ignition (RCCI) concept is demonstrated as a promising method to achieve high efficiency – clean combustion. Engine experiments were performed in a heavy-duty test engine over a range of loads. Additionally, RCCI engine experiments were compared to conventional diesel engine experiments. Detailed computational fluid dynamics modelling was then used to explain the experimentally observed trends. Specifically, it was found that RCCI combustion is capable of operating over a wide range of engine loads with near zero levels of NOx and soot, acceptable pressure rise rate and ringing intensity, and very high indicated efficiency. For example, a peak gross indicated efficiency of 56 per cent was observed at 9.3 bar indicated mean effective pressure and 1300 rev/min. The comparison between RCCI and conventional diesel showed a reduction in NOx by three orders of magnitude, a reduction in soot by a factor of six, and an increase in gross indicated efficiency of 16.4 per cen...

https://journals.sagepub.com/doi/pdf/10.1177/1468087411401548

Fuel reactivity controlled compression ignition (RCCI): a pathway to controlled high-efficiency clean combustion

Ignition and combustion control of HCCI (Homogeneous Charge Compression Ignition) in DI (Direct Injection) Diesel Engine were examined. In this study, double injection technique was used by Common Rail injection system. The first injection was used as an early injection for fuel diffusion and to advance the changing of fuel to lower hydrocarbons (i.e. low temperature reaction). The second injection was used as an ignition trigger for all the fuel. It was found that the ignition of the premixed gas could be controlled by the second injection when the early injection was maintaining low temperature reaction. It was found that as the boost pressure increased, ignition timing advanced slightly and the rate of pressure increase markedly decreased. The rate of pressure increase is one of the factors concerning operation limit in this combustion. Therefore, the VNT (Variable Nozzle Turbo-charger) was applied to the production engine to allow boost pressure control. Spray characteristics and combustion analysis images were investigated by the shadowgraph method. Luminous flame was not observed. The fluctuation due to the low temperature reaction was observed from the shadowgraph images. Many ignition points appeared in the combustion chamber. Low NOx and smoke were possible both in the first injection and in the second injection by this combustion. This HCCI concept was named as UNIBUS (Uniform Bulky Combustion System) by the author et al. and applied to the production engine (1KD-FTV, 3 liter-4cylinder) in August 2000 in the Japanese market.

HCCI Combustion in DI Diesel Engine

The detachment of liquid droplets from porous material surfaces used with proton exchange membrane (PEM) fuel cells under the influence of a cross-flowing air is investigated computationally and experimentally. CCD images taken on a purpose-built transparent fuel cell have revealed that the water produced within the PEM is forming droplets on the surface of the gas-diffusion layer. These droplets are swept away if the velocity of the flowing air is above a critical value for a given droplet size. Static and dynamic contact angle measurements for three different carbon gas-diffusion layer materials obtained inside a transparent air-channel test model have been used as input to the numerical model; the latter is based on a Navier-Stokes equations flow solver incorporating the volume of fluid (VOF) two-phase flow methodology. Variable contact angle values around the gas-liquid-solid contact-line as well as their dynamic change during the droplet shape deformation process, have allowed estimation of the adhesion force between the liquid droplet and the solid surface and successful prediction of the separation line at which droplets loose their contact from the solid surface under the influence of the air stream flowing around them. Parametric studies highlight the relevant importance of various factors affecting the detachment of the liquid droplets from the solid surface.

/pdf/dynamics-of-water-droplets-detached-from-porous-surfaces-of-r9i2w6er6n.pdf

Dynamics of water droplets detached from porous surfaces of relevance to PEM fuel cells.

A compression ignition type engine, wherein a first combustion where the amount of the recirculated exhaust gas supplied to the combustion chamber is larger than the amount of recirculated exhaust gas where the amount of production of soot peaks and almost no soot is produced and a second combustion where the amount of recirculated exhaust gas supplied to the combustion chamber is smaller than the amount of recirculated exhaust gas where the amount of production of soot peaks are selectively switched between and where the second combustion is switched to the first combustion when the temperature of the catalyst arranged in an engine exhaust passage is about to fall below the activation temperature.

Compression ignition type engine

Methods and apparatus for operating on images are described, in particular methods and apparatus for interest point detection and/or description working under different scales and with different rotations, e.g. for scale- invariant and rotation-invariant interest point detection and/or description. The present invention can provide improved or alternative apparatus and methods for matching interest points either in the same image or in a different image. The present invention can provide alternative or improved software for implementing any of the methods of the invention. The present invention can provide alternative or improved data structures created by multiple filtering operations to generate a plurality of filtered images as well as data structures for storing the filtered images themselves, e.g. as stored in memory or transmitted through a network. The present invention can provide alternative or improved data structures including descriptors of interest points in images, e.g. as stored in memory or transmitted through a network as well as datastructures associating such descriptors with an original copy of the image or an image derived therefrom, e.g. a thumbnail image.

Robust interest point detector and descriptor

A sequential turbocharger system for an internal combustion engine with an exhaust gas recirculation system. The sequential system includes a large-volume turbocharger and a small-volume turbocharger, which are arranged in series in the direction of the flow of gases. A bypass passageway is connected to an exhaust pipe to thereby bypass the turbine of the small-volume turbocharger, and an exhaust switching valve is arranged in the bypass passageway for controlling the flow of exhaust gas to the turbine of the small-volume turbocharger. The EGR system includes an exhaust gas recirculation passageway for introducing an amount of exhaust gas into the intake pipe of the engine. The exhaust gas for recirculation is taken out from the intake pipe at a position located between the turbines of the small-volume and large-volume turbochargers.

Hiromichi Yanagihara

Papers

HCCI Combustion in DI Diesel Engine

Dynamics of water droplets detached from porous surfaces of relevance to PEM fuel cells.

Compression ignition type engine

Robust interest point detector and descriptor

Sequential turbocharger system for an internal combustion engine