Engine failures

The accuracy of absolute risk results depends on (1) whether all the significant contributors to risk have been analyzed, (2) the realism of the mathematical models used to predict failure characteristics and accident phenomena, and (3) the statistical uncertainty associated with the various input data. The achievable accuracy of absolute risk results is very dependent on the type of hazard being analyzed. In studies where the dominant risk contributors can be calibrated with ample historical data (e.g., the risk of an engine failure causing an airplane crash), the uncertainty can be reduced to a few percent. However, many authors of published studies and other expert practitioners have recognized that uncertainties can be greater than 1 to 2 orders of magnitude in studies whose major contributors are rare, catastrophic events. 

The first case study shows how a knowledge of steel microstructures can help us trace the chain of events that led to a damaging engineering failure. 

The automobile, on the ground, will coast to a stop in case of engine failure, while the airplane will rapidly descend and may not be able to land safely. 

Engine failures over a five year span for 138 emergency generators are listed. Discussion of each type of failure is presented. Data listed includes percentage of failure over the population and time period. All failures were presumably insured by Hartford Steam Boiler and subject to functional inspections and audits. 

Hot corrosion32 is encountered in the operation of gas turbines between 730 and 1730°C. Operation of gas turbine engines in marine atmosphere is prone to hot corrosion, which involves oxidation and reaction with sulfur, sodium, vanadium and other contaminants present in the fuel or ilnet air. The consequence of this is the loss of protective action of chromium oxide on the blade and sometimes engine failure. 

Edward Ghali and Madhavarao Krishnadev, Physical and mechanical metallurgy of premature failure of tie rods of a cable stayed bridge , Engineering failure analysis, Volume 13, Issue 1, January 2006, pages 117-126. 

Carter T.J., Cornish L.A., Hydrogen in metals. Engineering Failure Analysis 8 (2001) 113-121... 

The exact temperature at which the cloud point is reached depends on the total n-alkane content of the fuel, the average size of the n-alkane molecules, their size distribution and chain structure (e.g. degree of branching). Conventional diesels contain as much as 20% of long-chain n-alkanes of limited solubility in the fuel. Pyrolysis-diesels from PE feedstocks can contain more than 40% long-chain n-alkanes. Paraffins crystallize at low temperature into very thin rhombic plates which can clog filters, transfer lines, and pumps, and can lead to engine failure at low temperatures. 

As diesel ages a fine sediment and gum forms in the fuel brought about by the reaction of diesel components with oxygen from the air. The fine sediment and gum will block fuel filters, leading to fuel starvation and engine failure. Frequent filter changes are then... 

Acta Metallurgica et Materialia Cement and Concrete Research Composite Structures Computers and Structures Corrosion Science Engineering Failure Analysis Engineering Fracture Mechanics European Journal of Mechanics A B International Journal of Fatigue International Journal of Impact Engineering International Journal of Mechanical Sciences International Journal of Non-Linear Mechanics International Journal of Plasticity... 

Chemists play a role in the addition of additives to improve the properties of motor oil. As steel and aluminum parts move closely against one another, friction between the two parts creates heat and wears away the metallic surfaces. This will lead to decreased efficiency, increased fuel consumption, decreased power output, and eventually engine failure. Engine additives are devised to combat these consequences. A list of engine additives follows however, rather than discussing each one in depth, we will discuss only some of the more important ones ... 

Thermal treatment appears to be the most readily available remedial action technology for dioxin. However, no data are available to confirm the maintainability, reliability and cost-effectiveness of transportable commercial systems. Through a competitive process, the USAF selected ENSCO Corporation for a full-scale field test of their rotary-kiln combustor. The test will be conducted at the NCBC, Mississippi and will involve treatment of approximately 9000 cubic yards of contaminated soil. An intense analytical program and engineering failure mode analysis will support the project. Testing is planned for November 1986 - March 1987. 

It would be improper to suggest that these results are the only ones obtained with PZ-236 in that durability fleet. However, the other tests were discontinued for reasons unrelated to the efficiency of PZ-236 as a catalyst. In one test, the converter was empty at 36,000 miles because of a hole in the outlet screen, while engine failures were cited as the cause for discontinuation of the other tests. In all the tests, however, the emissions were within the original 1975, and now 1977, standards at the time of test termination. 

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