Search Results

Biodiesel obtained from the transesterification of vegetable oil or animal fat is a promising renewable green alternative fuel for compression ignition engines. Compression ignition engines are particularly suitable for medium-to-large road, rail and marine use. This is due to their excellent efficiency and longer operation life which is about twice as much as that for spark ignition engines. The replacement of conventional diesel fuel with biodiesel fuel is an attractive solution since the latter is regarded as a renewable, biodegradable, non-poisonous, and oxygenated fuel. However, existing production technologies offer less competitive prices than petroleum-derived diesel due to high input feed and biodiesel purification costs. Non-edible vegetable oils such as waste cooking oils may be used as cheaper substitutes to virgin edible vegetable oils in the feed stream.

This paper reports experimental conversion of spent vegetable oil with bio-ethanol to long chain biodiesel fuel in presence of a new developed solid K3PO4 heterogeneous catalyst. Examined catalyst was synthesized following dipping impregnation of γ-Al2O3 solid support in an aqueous solution of potassium phosphate tri-basic K3PO4. K3PO4/γ-Al2O3 catalyst samples were distinguished based on their percentage loadings of K3PO4 (CK3PO4) and averaged particle size (dp). Produced catalyst samples were characterized in terms of their textural and surface properties using nitrogen adsorption-desorption isotherms and carbon dioxide & ammonia temperature programmed desorption techniques respectively. While the liquid phase of the product was analyzed using a GC-Mass spectroscopy technique. Ethanolysis runs were carried out following surface response methodology, central composite design (CCD).

For reduction of fuel consumption, a new device “Water Jacket Spacer” which improves temperature distribution of a cylinder block bore wall was developed. In the case of a conventional cylinder block, coolant flow concentrates at the bottom and middle region of the water jacket. While temperature of the upper bore wall is high (due to high-temperature combustion gas) the temperature of the lower bore wall is low, since its only function is to support the piston. When the developed spacer is inserted into a water jacket, the coolant flow concentrates at the upper part of the jacket. As a result, cooling ability to the upper bore wall was improved and temperature of lower bore wall was increased, thereby reducing fuel consumption.

Most automotive piston engines employ a front-mounted, belt-driven coolant circulation pump. The pump shaft is normally supported by a double row rolling-element radial contact bearing. The engineering analysis for an improved method of water pump bearing service load and life prediction is described here. This general analysis considers most of the design variations which are found among engines, water pumps, and bearings in current use. A rather thorough accounting has been made here of the various sources of bearing loading occurring in this application. Bearing life is determined according to the recently revised A.F.B.M.A. standards.

Water separation from diesel fuel is a critical requirement for modern diesel engines. The main reasons are: corrosion, wear on the fuel system, irregular combustion and acceleration of microbiological growth that clogs filters, pumps and prefilters. Due to this, agencies regulate water content in diesel (like DIN EN590 [1]) and biodiesel (like DIN EN14214 [2]). Also international institutes release standards to define the correct procedures, equipment and boundary conditions to confirm water separation filter efficiency (like ISO 4020 [3] and ISO/TS 16332 [4]). If you consider the Brazilian diesel conditions and fuel system configurations, the existing specifications, procedures and boundary conditions don't represent actual field conditions. The key differences are water droplet size, flow rate, temperature, biodiesel content and fuel aging effects which all impact the water separation properties.

It has been largely announced that automotive industry is going through a disruption moment regarding applied powertrain technologies due to the efforts to decrease CO2 and pollutant gases emission, mainly through related legislations of different countries and regions. European and Asian future legislations are going to demand some electrification introduction, whether hybrid or fully electric, but even different technologies such as fuel cells and synthetic fuels over the next few years. In Brazil, with the upswing of biofuels use, considering a well to wheel CO2 emission calculation, the usage of hydrated ethanol or ethanol mixed up with gasoline in different proportions is a great solution for a continuous and progressive automotive fleet decarbonization, in parallel or associated with electrification, in a favorable pace for the market conditions.

The type of pump (lobe, centrifugal, or piston) used in a circulation system determines the degree of mechanical and shear degradation inflicted upon the pigments present in a waterborne metallic paint. The visible effect of degrading the performance of a metallic paint is the extreme variation encountered in the appearance of the resulting automotive finish. We have determined through multiple angle spectrophotometry that lobe and centrifugal pumps initially cause a similar amount of degradation to the two-tone effect exhibited by a metallic finish. The degradation effect associated with a lobe pump was observed to dramatically increase with extended usage of the pump. Piston pumps were discovered to cause the least amount of paint degradation. A centrifugal pump having open impellers performed similar to a centrifugal pump with closed impellers.

This paper presents a hydraulic pump fault diagnosis method based on a discharge pressure pulsation model. This diagnosis method was based on the pressure signals measured at the discharge port of the pump. The obtained signals were transformed into frequency domain for performing wavelet analysis to separate the fault signals from the pressure signal at the time a fault occurs. This method was first evaluated via simulation analysis, and then validated against test data. Results showed that this wavelet based fault diagnosis method was capable of detecting pump failure using the outlet pressure pulsating signal.

Wavelet transform analysis is capable of revealing aspects of data that other techniques miss such aspects are trends, and discontinuities in higher derivates. This method can often compress or de-noise a signal without any appreciable degradation and it provides accurate information on the localization of energy content in time and frequency [1]. The Wavelet transform method has been applied to the analysis of combustion noise and piston slap in order to identify the effects on the engine structure vibration. The experimental results showed that combustion noise and piston slap were successfully detected from the acceleration signals picked up by external transducers in the outer wall of an in-line, 6 cylinder diesel engine.

Karanja biodiesel is prepared using Karanja oil and methanol by the process of transesterification. Use of Karanja oil methyl ester (KOME) in a 780 hp CIDI military engine was found to be a highly compatible alternative fuel with low emission characteristics. Engine was operated for 100 hours each using pure karanja biodiesel and mineral diesel fuel, respectively. These were subjected to long-term endurance tests. Lubricating oil samples, drawn from both fuelled engine after a fixed interval of 20 hours, were subjected to elemental analysis. Atomic absorption spectroscopy (AAS) was done for quantification of various metal debris concentrations. Wear metals were found lower for a biodiesel operated engine system. Lubricating oil samples were also subjected to ferrography indicating lower wear debris concentrations for a biodiesel-operated engine. Scanning electron microscopy was also conducted on the cylinder liner surfaces exposed to wear.

Since wear is a not a material property, but a tribological system property, it is of great importance to know the wear, friction and lubrication behavior of materials tested in bench equipment. This work presents reciprocating pin-on-plate bench tests results, with gas nitrided stainless steel pins and gray cast iron plates. The testing conditions were 0.5 and 3.2 Hz frequency, 20 and 600N applied load and 100 and 150 °C. Under these conditions, mild to severe wear transition was observed. It was noticed noise emission changes at wear transition. This noise change could be used to verify wear transition mechanism.

Three 1978 Ford Pinto 2300 cc vehicles were retrofitted to operate on neat methanol and driven for an 18-month period. The modification package included carburetor rejetting, upgraded fuel filtration and electric cold start assistance. Internal engine components (excepting camshafts) and the engine lubrication system were not modified. A conventional motor oil was used in all vehicles. Over 30,000 vehicle miles were accumulated in the test period. Wear metal samples were taken at 1000-mile intervals and analyzed for 16 metallic constituents using Direct Reading Emission Spectroscopy (DRES). Percentage fuel and water dilution were also measured. All oil samples showed abnormally high concentrations of lead and tin. Iron accumulation rates over the entire test were similar to those reported for gasoline engines. Maximum fuel or water dilution in any sample was 0.5%.

The wear mechanisms of the methanol engine were studied using dynamometer tests. Formic acid from methanol combustion mixes with the lubricant oil and attacks the metal surfaces. The iso tacho prorissis method was successfully applied to analyze the formic acid content of the used oil. A large amount of condensed water is also formed by methanol combustion and accelerates the wear. Wear can be effectively reduced by shortening lubricant oil change intervals, by using a special oil and by durable surface treatment of engine parts.

A laboratory wear test is used to evaluate the wear protection properties of new and used engine oils formulated for FFV service. Laboratory-blended mixtures of these oils with methanol and water have also been tested. The test consists of a steel ball rotating against three polished cast iron discs. Oil samples are obtained at periodic intervals from a fleet of 3.0L Taurus vehicles operating under controlled go-stop conditions. To account for the effects of fuel dilution, some oils are tested before and after a stripping procedure to eliminate gasoline, methanol and other volatile components. In addition to TAN and TBN measurements, a capillary electrophoresis technique is used to evaluate the formate content in the oils. The results suggest that wear properties of used FFV lubricants change significantly with their degree of usage.

Axial piston type pumps are often exposed to severe operating conditions because of the duty cycle, the environment, or, in some situations, poor maintenance and even abuse. The detrimental effects on the pump and the hydraulic system as a result of these adverse conditions are often not known or predictable. In this study, four controlled severe operating conditions were imposed on four identical axial piston type pumps. They included 1) constant high load pressure and normal fluid temperature, 2) constant high load pressure and elevated fluid temperature, 3) cyclic load pressure and normal fluid temperature, and 4) cyclic load pressure and elevated fluid temperature. The tests were long-term; they were run continuously for up to 5000 hours. The pump wear was monitored in all cases using ferrography. In addition, the condition of the fluid was monitored and the circuit filters were examined periodically. The results of the findings are presented in this paper.

The automotive electrical fuel pumps for gasoline and alcohol fueled vehicles engines are lubricated by the fuel itself. The new flexible fuel engine technology, specially in Brazil, the fuel pump is designed to be lubricated by gasohol (E22) or strait hydrated ethanol fuel but it is also exposed to the variable gasoline/alcohol blends in the flex-fuel engines. This paper presents the influence of different fuel blends, ethanol and gasohol, to the fuel pump wear and corrosion behaviors. The tested fuel pumps were designed for gasohol only engines. The fuel pumps were tested in a bench device, which simulates the vehicle fuel circuit, using gasohol (E22), hydrated ethanol (E100) or 60 % in volume ethanol-gasoline mixture (E60). The scanning electron microscopy examinations and roughness measurements were performed for tribological analysis of fuel pump gears. The observed wear and/or other deterioration mechanisms were mainly due to the abrasion and corrosion.

The characteristic wear of electroplated chromium on piston rings has changed over the past 15 years. The reasons for the change are discussed and a theory proposed for the wear mechanism. The theory is supported by engine test results, radioactive ring and cylinder studies, and metallographic exhibits.

A new bench tester for laboratory simulation of piston ring and cylinder wear has been developed. Tests are made using liner segments which bear against a reciprocating piston ring. Temperatures up to 550°C, and loads and speeds representative of the most severe top ring conditions may be imposed. A precision oil spray system delivers the desired quantity and quality of oil to the wear interface. The computer controlled simulator duplicates the desired test cycle, and displays and stores data on friction forces and friction coefficients as the test proceeds. In this paper results are presented from the simulator for production and prototype ring and liner combinations, including ceramic coatings for potential use in advanced diesel engines. The importance of the method of oil delivery on test repeatability is emphasized. Some comparisons with Cameron Plint bench tests and firing engine results are presented.

FEM modeling was used to reduce the weight of engine reciprocating parts (pistons and piston pins) in order to reduce engine vibration and aid in the weight reduction of other engine pans. A non-dimensional number using the Mises stress σM /σ0.2 (θ) was used to improve the accuracy of simulation. It was found that changes in piston shape could compensate for increased stress due to reduced piston wall thicknesses, resulting in effective weight reduction for this part. Reduced engine weight not only improves performance but also lowers fuel consumption. This, combined with less engine vibration, leads to a lighter and more efficient vehicle.

In order to improve the fuel economy of automobiles, further increase in the efficiency of gasoline engines is strongly demanded. In particular, reducing the weight of the pistons plays a major role. The pistons in this engine were connected to the connecting rods by a spherical joint bearing instead of a conventional piston pin, and a thin-walled piston top with radial rib structure was employed to reduce the piston weight. To ensure the required piston functions, lubrication of the bearing, cooling of piston top and the skirt design for smooth motion were important challenges to realize weight reduction of the spherical joint piston. In this paper, firstly, the lubrication characteristics of the ball were evaluated using a high frequency fluctuating load device to minimize the diameter of the ball of the spherical bearing. In the next step, cooling of the thin-walled piston top structure by oil fed through the connecting rod was investigated.