Contamination of brake fluid by power steering fluid.
Analysis of a contaminated brake fluid revealed the contaminant to be power steering fluid. The sample received at the laboratory presented two immiscible phases, which were both organic. Both fluids were analyzed by GC-MS and compared with a library of known automotive fluids. The bottom layer (brake fluid) consisted of glycols while the top layer (power steering fluid) consisted of aliphatics ranging from C16 to C25+. An interesting phenomenon of diffusion of some of the glycols from the brake fluid phase into the power steering fluid phase was observed and needs to be taken into consideration in the interpretation of the results.
Capillary Column Gas Chromatography in the Examination of High Relative Molecular Mass Petroleum Products
Abstract Examples are presented of capillary gas chromatograms of some petroleum-based lubricants. It is shown that different types of product are readily distinguishable, and that ten commonly used automobile engine oils can be differentiated from one another. A case work example is given.
Computational Analysis of a Double-Nozzle Crossflow Hydroturbine
The crossflow turbines commonly used in small hydropower systems have a single nozzle. We are unaware of any studies of double-nozzle crossflow turbines which could have twice the power output of the single-nozzle design by doubling the flow through the same runner, with a high maximum efficiency. We present a computational analysis of a double-nozzle crossflow turbine, to determine the turbine efficiency and fundamental flow patterns. This work was based on a single-nozzle crossflow turbine with a maximum efficiency of 88%, one of the highest reported in the open literature through extensive experimental measurements. Previous numerical studies on this turbine have shown that the water flow in the runner was confined to less than half the runner periphery, implying that the other half could be used to double the runner power output by employing a second nozzle. We show that adding a second, identical nozzle without making any other changes to the design achieves a doubling of the power output. The dual-nozzle turbine, therefore, has the same efficiency as the original turbine. We also investigate the use of a slider to control the flow at part-load and show that part-load efficiency of the double-nozzle is very similar to that of the original turbine. This demonstrates the feasibility of using two nozzles for crossflow turbines.