In the present study, three different fluids with different volumes of nano materials(Al2O3) in the Reynolds range of 3 to 48 thousand were investigated for the purpose of evaluating the effect of using nanofluid in heat exchangers. The converter in the submarine engine come to use of as a motor oil cooler. The results show that the addition of nanoparticles to the base fluid in the lower reynolds results in a higher performance factor in the exchanger. By increasing the volumetric percentage of nanoparticles, the converter's performance factor decreases. Optimum mode and maximum heat exchanger performance, in all volumetric percentages, occurs in Reynolds 20, 000 for water and 12, 000 for ethylene glycol. In other words, the choice of base fluid with a higher performance factor depends on the Reynolds number range. Also, this study examined sea water as a cooling fluid available to the marine diesel engine.

Nowadays, engine oils have various functions, which one of the most important of them is the lubrication of different parts in the engine, for reducing the rate of the friction and the wear. Oil properties are mainly a result of additives, which are added to the oil to improve requirement properties. Recently, nano-particles are also appeared as a new kind of additives, due to their special properties.The purpose of the present research is surveying the amount of the ability of nano-particles and it is a kind of the functionality to improve anti-wear properties and the heat-conduction ability and controlling developed variations of the engine oil, on its properties including: the viscosity, the pour point and the flash point. For this purpose, carbon nano ball particles, by using the planetary ball mill, were dispersed inside the Behran Pishtaz engine oil, SAE 20W50. Then, tests were done for investigating mentioned properties. Obtained results showed that the thermal conductivity coefficient of the oil containing carbon nano ball particles with 0.1wt%, increased about 18 percent with respect to the base oil. Also, upon results of the four ball test, the amount of the wear, in the oil contains nano-particles reduced 5 percent with respect to the oil without nano-particles.

In this study, the performance of anti-wear in engine oil which contain nanomaterialadditive has been compared and evaluated to conventional engine oil, by using laboratory tests. Forthis purpose, magnetic iron oxide nanoparticles (Fe3O4) as a nanomaterial additive were selectedto use in Iranol Racing engine oil, SAE 10W40. At first the stability of the nano-fluid, obtainedby the nanoparticles, was confirmed by using UV and zeta potential devices. The iron oxidenanoparticles were characterized by scanning tunneling microscopy (STM), energy dispersiveX-ray spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR). The nanoparticleshave a diameter in the range of 8-13 nm. Size distribution of nanoparticles by dynamic lightscattering (DLS) was also investigated. Anti-wear performance of Fe3O4 nanoparticles in multigradeengine oil was evaluated by means of the four ball and falex test. The results generallyindicate the improvement of anti-wear performance engine oil which was prepared by addingnanoparticles. Magnetic iron oxide nanoparticles with concentration of 0. 1 percent, increase weldstrength from76. 32 to 92. 74 kgf and load wear index (LWI) from 250 to 315 kgf, in the four balltest. Additionally it has increased the falex test results (linear load carrying) from 1160 to 1220 lbf, compared to conventional engine oil.

Introduction: Vehicle engine id one of the main sources of noise which its level is influenced by various parameters. The aim of this study was to investigate the impact of motor oils quality before and after oil change on the variability of vehicle engine induced noise level. In this study it is tried to follow-up the efficacy of motor oil quality on engines sound level.Material and Method: First, engine noise of 94 vehicles were recorded for 30 seconds before and after oil change and all the vehicles technical information including mileage, type of motor oil, and type of vehicle were registered. Following, the recorded noises were calibrated in semi-anechoic chamber and the sound pressure levels were measured with A and C-weighting network and main octav bands, using a sound level meters. The obtained results analyzed using SPSS software version 17.Results: The effects of motor oil quality on different noise levels of engines were determined and a significant reduction in noise level of vehicles engine was observed. Investigation of the relationship between mileage and motor oil quality on various engines sound level manifested that vehicles with mileage ranged 100000-150000 miles had significant reduction in their sound pressure levels in comparison with other vehicles.Conclusion: The results revealed that engine oil is among factors reducing the vehicle engine induced noise level. Moreover, the engine oil type and the vehicle mileage are key variables which determine the impact of engine oil quality on reduction of the sound level of vehicles engine.

Delay of oil pressure increasing at the engine starting can effect on wear rate in the internal combustion engine. This paper investigates oil priming behavior of spark ignition engine using two types of gyrator oil pump. So, oil pressure in main gallery and cylinder head is measured with high response oil pressure sensor that synchronized with engine speed in different status of engine starting. Results shows the maximum delay of oil priming is about 2. 5 second that is occurred in oil/oil filter changing. Using oil pump No. 2 after 12 hours, can decrease delay of oil priming from 1. 93 second to 1. 24 second in EF7 engine. Due to using hydraulic tappet technology in this engine, delay of oil priming effect on the engine wear rate and also hydraulic tappet life time. Results show that engine oil pump No. 2 can decrease crank shaft rotation in oil/oil filter changing, cold starting and warm staring status from 58, 45 and 18 revolution to 32, 19 and 11 revolution.

In this research, biodiesel was initially produced from waste vegetable oil by transesterification reaction. The main properties of this fuel were compared with the ASTM D-6751 standard. Then, performance of MF-399 tractor engine was tested and evaluated by using 5 to 25 percent biodiesel and diesel blends. Test results showed that, the power and torque of MF-399 tractor engine were increased, using biodiesel and diesel blends. This is because of good combustion of biodiesel due to high oxygen content of this fuel. There was also a slight increase in the fuel consumption and specific fuel consumption of biodiesel and diesel blends due to low calorific value of biodiesel. Results show that the B5D95 blend has the best performance and the lowest increase in specific fuel consumption among the other blends. The fuel consumption and specific fuel consumption of B25D75 was lower than the B20D80 blend. Therefore, if the goal is using high amount of biodiesel, B25D75 blend is recommended for use in MF-399 tractor engine.

1. Introduction: Given that advances have been made toward the use of carbon-free or low-carbon energy sources in the modern sciences (Simpson and Tatsuoka, 2008), the development and optimization of more environmentallyfriendly methods are required. Biological practices have their own sensitivity due to their dealings with living organisms. The feasibility of the use of the calcium carbonate precipitation method in the sandy soils contaminated with hydrocarbon pollutants and the use of bacterial flocculation have been recently investigated (Cheng and Shahin, 2017). The purpose of the present research is to investigate the variation of geotechnical parameters of sandy soils contaminated with motor oil. . .