Experimental investigation on the influences of varying injection timing on the performance of a B20 JOME biodiesel fueled diesel engine / S. Jaichandar and K. Annamalai

This experimental study aims to optimize the injection timing to achieve higher performance from biodiesel fueled Direct Injection (DI) diesel engine. Experiments were performed using a naturally-aspirated single cylinder DI diesel engine equipped with a conventional jerk type injection system to study the effects of varying injection timing on the combustion, performance and exhaust emissions using a blend of 20% Jatropha Oil Methyl Ester (JOME) by volume with diesel. The test results showed that improvement in terms of brake thermal efficiency and specific fuel consumption for the engine operated at retarded injection timing, particularly at 21o bTDC. Substantial improvements in reduction of emission levels particularly oxides of nitrogen (NOx) were observed for retarded injection timing of 21o bTDC. Compared to the engine operated at standard injection timing of 23o bTDC, the retarded injection timing of 21o bTDC provided a better performance of 2.27% and 3.4% in terms of BTE and BSFC respectively and NOx emission level improvement of 4.5%. However, CO, UBHC and smoke emission levels were slightly deteriorated compared to standard injection timing operation. It has also been found that retarding the injection timing lowers marginally ignition delay, peak in-cylinder pressure and maximum heat release rate

An Intelligent FPGA Based Anti-Sweating System for Bed Sore Prevention in a Clinical Environment

Bed sores, a common problem among immobile patients occur as a result of continuous sweating due to increase in skin to bed surface temperature in patients lying on same posture for prolonged period. If left untreated, the skin can break open and become infected. Currently adopted methods for bed sores prevention include: use of two hourly flip chat for repositioning patient or use of air fluidized beds. However, the setbacks of these preventive measures include either use of costly equipment or wastage of human resources. This paper introduces an intelligent low cost FPGA based anti-sweating system for bed sores prevention in a clinical environment. The developed system consists of bed surface implanted temperature sensors interfaced with an FPGA chip for sensing the temperature change in patient’s skin to bed surface. Based on the temperature change, the FPGA chip select the - mode (heater/cooler) and speed of the fan module. Furthermore, an alarm module was implemented to alert the nurse to reposition the patient only if patient’s skin to bed surface temperature exceeds a predefined threshold thereby saving human resources. By integrating the whole system into a single FPGA chip, we were able to build a low cost compact system without sacrificing processing power and flexibility

The Influence of Piston Bowl Geometries on In-Cylinder Air Flow in a Direct-Injection (DI) Diesel Engine for Biodiesel Operation / S. Jaichandar, E. James Gunasekaran and A. Gunabalan

Thermal efficiency improvement, fuel consumption and pollutant emissions reduction from biodiesel fueled engines are critical requirements in engine research. In order to achieve these, a rapid and better air-fuel mixing condition is desired. The mixing quality of biodiesel with air can be improved by selecting the best engine design particularly combustion chamber design and injection system parameters. The present work investigates the effect of varying the piston bowl geometry on the air flow characteristics such as swirl velocity, Swirl Ratio (SR), and Turbulent Kinetic Energy (TKE) inside the engine cylinder. The piston’s bowl geometry was modified into several configurations that include Shallow depth combustion chamber (SCC), Toroidal combustion chamber (TCC), Shallow depth reentrant combustion chamber (SRCC) and Toroidal re-entrant combustion chamber (TRCC) from the standard Hemispherical combustion chamber (HCC), without altering the compression ratio of the engine. A commercially available CFD code STAR-CD was used to analyze the in-cylinder flow at different conditions. Flow conditions inside the cylinder were predicted by solving momentum, continuity and energy equations. The results confirmed that the piston bowl geometry had little influence on the in-cylinder flow during the intake stroke and the first part of compression stroke i.e. up to 300oafter suction TDC. However, the piston bowl geometry plays a significant role in the latter stage of the compression stroke i.e. beyond 300oafter suction TDC to compression TDC. The intensity of maximum swirl velocity at the end of compression stroke for TRCC was observed higher as 18.95 m/s and a strong recirculation was observed due to the geometry. Compared to baseline HCC the TRCC had higher, maximum swirl ratio and turbulent kinetic energy by about 28% and 2.14 times respectively. From the analysis of results, it was found that TRCC configuration gives better in-cylinder flows

Non-descanned multifocal multiphoton microscopy with a multianode photomultiplier tube

Multifocal multiphoton microscopy (MMM) improves imaging speed over a point scanning approach by parallelizing the excitation process. Early versions of MMM relied on imaging detectors to record emission signals from multiple foci simultaneously. For many turbid biological specimens, the scattering of emission photons results in blurred images and degrades the signal-to-noise ratio (SNR). We have recently demonstrated that a multianode photomultiplier tube (MAPMT) placed in a descanned configuration can effectively collect scattered emission photons from each focus into their corresponding anodes significantly improving image SNR for highly scattering specimens. Unfortunately, a descanned MMM has a longer detection path resulting in substantial emission photon loss. Optical design constraints in a descanned geometry further results in significant optical aberrations especially for large field-of-view (FOV), high NA objectives. Here, we introduce a non-descanned MMM based on MAPMT that substantially overcomes most of these drawbacks. We show that we improve signal efficiency up to fourfold with limited image SNR degradation due to scattered emission photons. The excitation foci can also be spaced wider to cover the full FOV of the objective with minimal aberrations. The performance of this system is demonstrated by imaging interneuron morphological structures deep in the brains of living mice.Grant RO1 EY017656National Institutes of Health (U.S.) (9P41EB015871)5 R01 NS0513204R44EB012415National Science Foundation (U.S.) (CBET-0939511)Singapore-MIT Alliance for Research and TechnologyMIT Skoltech InitiativeHamamatsu CorporationDavid H. Koch Institute for Integrative Cancer Research at MIT (Bridge Project Initiative

Performance and exhaust emission analysis on pongamia biodiesel with different open combustion chambers in a DI diesel engine

487-491This study presents effects of combustion chamber geometries (hemispherical, toroidal and shallow) by using pongamia oil methyl ester (POME) blended with diesel (20:80) in a single cylinder, direct injection diesel engine. Brake thermal efficiency for toroidal combustion chamber was found higher than that of other two combustion chambers. Significant improvement in reduction of particulates, carbon monoxide and unburnt hydrocarbons was observed for toroidal combustion chamber compared to the other two. However, nitrogen oxides were slightly higher for toroidal combustion chamber

AN ASSESSMENT OF VARIOUS NANOADDITIVES AND TRIBO-CORROSION WITH WASTE COOKING BIODIESEL FUELED IN A DIESEL ENGINE

The waste cooking biodiesel's steady-state coefficient of friction rate of fuel blends are B90 (18.2%), B60 (7.2%), B20 (16.72%), B10 (30.8%), and diesel (38.77%) higher compared with B40 fuel blend and wear scar diameter of the fuel blends from B40 to B100 had a minimal range of 0.5mm. The flash temperature parameter results higher from B40 to B100 fuel blends, and the corrosion rate was minimal for B40 and B50 fuel blends. Afterward, the fuel blend B40 (40% WCO+60% Diesel fuel) was chosen as fuel, along with Cerium (25ppm), Zinc (25ppm), and Titanium nanoparticles (25ppm) were selected as fuel additives. The B40+D60+Titanium (25ppm) blend resulted in improved BTE and 3.83% lowered BSEC comparison with diesel fuel. Then the fuel blend, B40+D80+Titanium (25ppm), resulted in 2.08% reduced HC, 36.36% CO, and 16.25% smoke emissions, along with marginally 8.5% higher NOx emissions comparison with diesel fuel. Also, the fuel blend, B40+D80+Titanium (25ppm) combustions characteristics are the equivalent trend of cylinder pressure (58.82 bar) and HRR (66.65 J/deg CA) related to diesel fuel at peak load.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Effects of varying injector opening pressure on the performance of a B20 JOME biodiesel fueled diesel engine / S. Jaichandar...[et al.]

The present work examines the influence of Injector Opening Pressure (IOP) on Jatropha oil fueled Compression Ignition (CI) engine. A Direct Injection (DI) type diesel engine was tested with a blend of 20% Jatropha Oil Methyl Ester (JOME) with 80% diesel (B20) on volume basis. The engine was run on four different injector opening pressures viz. 190, 210, 220 and 230 bar along with standard IOP of 200 bar. For all IOPs, performance considerations like brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), combustion factors such as cylinder pressure and ignition delay and emission issues such as CO, UBHC, smoke opacity and oxides of nitrogen (NOx) were investigated. From the experimental examinations it was observed that IOP of 220 bar showed improvement in terms of BTE and BSFC by about 2.3% and 4.4%. Considerable enhancement in reduction of emission levels particularly for CO, UBHC and smoke were also observed for increased IOP of 220bar by about 26.4%, 12.96% and 3.4% respectively, compared to the engine operated at standard IOP of 200 bar. However, NOx emission level was deteriorated compared to normal IOP. It was also found that increasing the IOP, lowered ignition delay and increased the in-cylinder pressure