Automatic Predicting Torsional Vibrations on Main Propulsion Plants, Installed Two-Stroke Diesel Engines: Algorithms and Software

The main propulsion plant (MPP) on marine sea-going ships consisting of a diesel engine as the main engine and driving the ship propeller is with the torsional vibrations to be calculated in accordance with the Rules for the Classification and Construction of Sea-Going Ships. The Rules are given by one of maritime registers in the world that are the members of IACS, such as Russian Maritime Register of Shipping (RMR), DNV, ABS, at el. The TV calculation (TVC) on the MPP usually is certainly a monumental calculation task and is conducted with special software for TVC. Nowadays, in accordance with the Rules, almost modern software products for TVC have the abilities to calculate the TVs at normal working regimes and at misfire regimes (called by Normal or Misfire regimes relatively) with only one of cylinders of marine diesel engine (MDE) while engine speed range covers from the minimum to maximum values of the operation speeds. The paper presents improved algorithms and software for automatic calculating the TVs (SATVC) at the Normal and the Misfire regimes, in which the misfiring processes appear not only in one cylinder, but also in two of the MDE cylinders together. The SATVC was based on the made mathematical models, algorithms and coded in LabView by authors. The SATVC consists of modules for automatic calculation of freedom TVs (FTVs), excited torsional moments (ETM), excited TVs (ETVs), permitted torsional pressures (PTP), and common management (CTVC). TVC at every working regime of MDE was automatically conducted in the following procedure: Configuration of the MPP for TVC; Calculation of FTVs; Calculation of ETM; Calculation of ETVs); Calculation of ETVs, and solution of the TVC in considered working regime. The working regime of MDE was modeled by a vector of firing coefficients (VFC) of every MDE cylinder.

IMPACT OF ADDING OXYGENATES TO DIESEL FUEL ON ENGINE’S PERFORMANCE AND EMISSIONS

??investigation of performance and emission of conventional a four-stroke, single-cylinder direct injection (DI) diesel engine at variable engine speed range from (1500 to 3000 rpm), carried out at steady-state tests conditions with diesel fuel and biodiesel which is produced from sun flower oil mixed with the higher alcohol. The blends effects on the performance and emission for the blended fuels measured and compared. 10% and 15% of Pentanol, Octanol added to the biodiesel blended with diesel for various test conditions. The experimental results showed an approximately 2–9% increase in the brake-specific fuel consumption (BSFC) for the prepared blends of pentanol and octanol due to the lower heating value (LHV), with higher brake thermal efficiency compared to diesel fuel. With expressively reduction of (9.8-21% vol.) in carbon monoxide (CO), and total unburned hydrocarbons (THCs) of (65-78.3% ppm), and nitric oxides (NOx) (44.4–52.9% ppm). The combustion analyses showed that the addition of biodiesel to conventional diesel fuel decreased the ignition delay and reduced the properties. These results indicated that biodiesel and higher alcohol could be used without any engine modifications as an alternative and environmentally friendly fuel.

Performance Characteristics of Philippine Hydrous Ethanol-Gasoline Blends: Preliminary Findings

To reduce dependence on imported fossil fuels and develop indigenous biofuels, the Philippines enacted the Biofuels Act of 2006 which currently mandates a 10% by volume blend of 99.6% anhydrous bio-ethanol for commercially sold Unleaded and Premium gasolines. To urge a regulation review of the anhydrous requirement and examine the suitability for automotive use of hydrous bioethanol (HBE) blends, preliminary engine dynamometer tests at 1400–4400 rpm were conducted to measure specific fuel consumption (SFC) and power. In this study, HBE (95 % ethanol and 5% water by volume) produced from sweet sorghum using a locally-developed process, was blended volumetrically with three base gasoline fuels — Neat, Unleaded, and Premium. The four HBE blends tested were 10% and 20% with Neat gasoline, 20% with Unleaded gasoline, and 20% with Premium gasoline. For blends with Neat gasoline, the SFC of the 10%HBE blend was comparable with to slightly higher than Neat gasoline. The SFC of the 20%HBE blend was comparable with Neat gasoline up to 2800 rpm and lower beyond this speed thus being better overall than the 10%HBE blend. Compared to their respective commercial base fuels, the HBE-Unleaded blend showed lower SFC while the HBE-Premium blend yielded slightly higher SFC over most of the engine speed range. Between commercial fuel blends, the HBE-Unleaded blend gave better SFC than the HBE-Premium blend. Power was practically similar for the fuels tested. No engine operational problems and fuel blend phase separation were encountered during the tests. This preliminary study indicated the suitability of and possible optimum hydrous bio-ethanol blends for automotive use under Philippine conditions.

Modelling of Electrically-Assisted Turbocharger Compressor Performance

For the purposes of design of a turbocharger centrifugal compressor, a one-dimensional modelling method has been developed and applied specifically to electrically-assisted turbochargers (EAT). For this purpose, a mix of authoritative loss models was applied to determine the compressor losses. Furthermore, an engine equipped with an electrically-assisted turbocharger was modelled using commercial engine simulation software (GT-Power) to assess the performance of the engine equipped with the designed compressor. A commercial 1.5 L gasoline, in-line, 3-cylinder engine was selected for modeling. In addition, the simulations have been performed for an engine speed range between 1000 and 5000 rpm. The design target was an electric turbocharger compressor that could meet the boosting requirements of the engine with noticeable improvement in a transient response. The results from the simulations indicated that the EAT improved the overall performance of the engine when compared to the equivalent conventional turbocharged engine model. Moreover, the electrically-assisted turbochargers (EAT) equipped engine with power outputs of 1 kW and 5 kW EAT was increased by an average of 5.96% and 15.4%, respectively. This ranged from 1000 rpm to 3000 rpm engine speed. For the EAT model of 1 kW and 5 kW, the overall net reduction of the BSFC was 0.53% and 1.45%, respectively, from the initial baseline engine model.

CO2 concentration from turbocharged common rail diesel engine dually fueled with compressed biomethane gas controlled at optimum ratio

The objectives of this study are to investigate the carbon dioxide (CO2) concentration from the compressed biomethane gas (CBG) and diesel dual-fueled diesel engine and to compare the CO2 concentration produced from the dual-fueled and the diesel-fueled engines. The duration of CBG injection was controlled by following the optimum ratio of the CBG obtained from the previous study. During the test, the engine speed was varied from 1,000 to 4,000 rpm and the engine torque was maintained to be 25, 50, 75 and 100% of the maximum engine torque. Experiment was divided into two parts consisting of the dual-fueled and the diesel-fueled modes. From the dual-fueled mode, when the engine speed increased, the CO2 concentration decreased. Because the optimum ratio of the CBG and the volumetric efficiency decrease during the high engine speed range, the proportion of the diesel increases, the incomplete combustion occurs. The unburned carbon oxidizes to be the CO in higher proportion than the CO2, thus, the CO2 consequently decreases. From the CO2 comparison, the dual-fuel mode produced the CO2 nearly the same as that of the diesel-fuel mode during the low engine torque. On contrary, the dual-fuel mode had higher CO2 concentration during the high engine torque.

Influence of CME-Diesel Blends on the Performance of a Light Duty Common Rail Direct Inject Engine

Coconut Methyl Ester (CME) is the main feedstock used for biodiesel in the Philippines, As of this year only 2% of CME is mandated to be blended in locally distributed fuel, but by 2016 the target is to increase the mandated biofuel blend to 5%. Given the mixed results about the effect of biofuels blends in engine perfomance by various studies it is imperative to further assess the impact of the target biodiesel blends. The effect CME Biodiesel blends in the performance of a light duty automotive common rail direct injection engine is determined in this study. Total of six fuel blends – B0 (Neat Diesel), B2 (2%CME, 98%B0), B5 (5% CME, 95%B0), B10 (10%CME, 90%B0), B15 (15%CME, 85%B0) and B20 (20%CME, 80% B0) were tested for performance at 100% load with varying speeds from 800 RPM to 2400 RPM at an interval of 400 RPM. At this typical engine speed range, no significant differences for biodiesel blends versus neat diesel were observed for torque.

Performance Measurement and Analysis of Vertical Shaft V-Twin Engines, and Comparison With Horizontal Engines of the Same Model Class

Over the past two years, we have conducted two experimental test series aimed at examining typical performance of gasoline V-twin engines in the 25 hp class, and the suitability of assumed mechanical efficiency in correcting observed measurements. We used engines manufactured by Honda, Kawasaki, Kohler, and Subaru (Robin). The tests were conducted at the Engines Laboratory of the California Polytechnic State University, San Luis Obispo (Cal Poly). The Kohler engines are fuel injected while the others three are carbureted. We tested twenty-eight engines in total. The first series of tests included four horizontal shaft engines from each of the manufacturers (sixteen in total), and followed the general guidelines of SAE standard J1349-199506. This paper reports primarily on the subsequent series of twelve engine tests, which included vertical shaft engines of an equivalent family (and displacement class), from three of the original manufacturers: Honda, Kawasaki and Kohler. All three engines have roughly the same engine speed range (2000–4000), and all three reportedly reach peak power at 3600rpm. This is typical of small engines, which may be used to drive small generators in addition to being installed on other equipment. Vertical shaft engines are typically tested on a vertical shaft dynamometer, or one that converts from a horizontal to vertical position. However, these dynamometers are typically either of the water brake or eddy current type. They cannot motor the engine, and thus cannot measure friction mean effective pressure (FMEP) directly, which is the preferred method to quantify friction and mechanical efficiency for engine testing. However, testing vertical shaft engines on a horizontal shaft motoring dynamometer requires an angled gear drive to mate the engine to the dynamometer, and thus adds a loss that complicates the accurate measurement of FMEP and brake output. We present here results using a simple method with which our measurements can be corrected for this loss, in tests of this sort. The study thus expands on our previous results, and shows the extent by which engine to engine variations are affected by shaft configurations, within a given model family, and within similar offerings by different manufacturers. We also analyzed our results to contrast the methodology of SAE J1349-199506 with that of the updated J1349-201109, specifically with respect to using an assumed value of mechanical efficiency to characterize FMEP and correct dynamometer data on small, general utility engines.

Active Control of Vehicle Transient Powertrain Noise Using a Twin-FXLMS Algorithm

Powertrain noise is a major component of vehicle interior noise and thus has a significant effect on the overall sound quality. It is typically dominated by harmonics in the lower audible frequency range, which are directly related to the engine firing orders. In order to achieve a more comfortable environment and pleasing driving experience, an active noise control (ANC) applying advanced filtered-x least mean squares (FXLMS) algorithm is employed to reduce the vehicle interior noise by targeting these harmonics. The proposed ANC system is designed to control multiple orders of the engine noise response simultaneously. It is also uniquely formulated with a twin-FXLMS algorithm to prevent harmonic interference that often resulted in overshoot at some adjacent orders, especially at low engine speed range where the reference sinusoids are close together. In fact, the interference issue is one of the critical problems that previously plagued the use of the conventional FXLMS algorithm. The basic design of the twin-FXLMS algorithm splits the adaptive filter into two sets. This allows different sum of reference sinusoids to be fed into each adaptive filter in order to widen the frequency separation between two adjacent harmonics. Finally, the performances of proposed twin-FXLMS are validated by numerical simulations.

Energy Analysis of Cooling Pump in Internal Combustion Engine

This study is conducted to analyze the energy use by cooling pump in internal combustion engine (ICE). The main focus of the experiment is to analyze the radiator heat transfer and the cooling pump power. The heat transfer rate of radiator is determined by conducting an experiment on an ICE. Thermocouples and an anemometer are used for temperature and air velocity measurement respectively. The cooling pump power is determined through dynamometer test. These experiments are conducted only for engine speed range of 1000rpm to 1500rpm to avoid overheating when belt is dismantled. The engine running at 1000rpm to 1500rpm produces about 1.2kW to 2.5kW power and rejects heat at rate of 0.20kW to 0.3kW, representing 13.0% to 19.1% of the total energy lost. The cooling pump power is approximately 0.13–0.19kW which is approximately 7.6% of the engine power output.