Engine panel seals for hypersonic engine applications: High temperature leakage assessments and flow modelling

A critical mechanical system in advanced hypersonic engines is the panel-edge seal system that seals gaps between the articulating horizontal engine panels and the adjacent engine splitter walls. Significant advancements in seal technology are required to meet the extreme demands placed on the seals, including the simultaneous requirements of low leakage, conformable, high temperature, high pressure, sliding operation. In this investigation, the seal concept design and development of two new seal classes that show promise of meeting these demands will be presented. These seals include the ceramic wafer seal and the braided ceramic rope seal. Presented are key elements of leakage flow models for each of these seal types. Flow models such as these help designers to predict performance-robbing parasitic losses past the seals, and estimate purge coolant flow rates. Comparisons are made between measured and predicted leakage rates over a wide range of engine simulated temperatures and pressures, showing good agreement

Standing Out from the Crowd: The Real Effects of Outliers

We study the impact of outlier opinions – extreme views voiced by individuals – in financial markets. Using analyst forecasts as a laboratory, we show that market participants respond to the arrival of extremely optimistic forecasts, instead of ignoring them as noise. An outlier forecast subsequently moves group consensus and begets more extreme forecasts by peers. Outlier forecasts also generate stronger market reactions from investors, more media coverage, and more conservative management guidance. Further analyses reveal that issuing outlier forecasts increases an analyst’s chance to cover more important clients of his employer. Outlier forecasts are also more likely to take place when an analyst’s reputation cost is lower and information uncertainty is high. These findings suggest that the propensity for expressing extreme views is situational and that personal incentives are the likely cause at play