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This paper describes Pratt &Whitney's pioneering work in “constrained dynamic inversion,” a control algorithm architecture for multivariable systems that must operate tight to limits. A hallmark of gas turbine control is the prevalence and fundamental importance of tightly holding limits. When constrained dynamic inversion is applied to gas turbine systems control, this algorithm enables operation closer to physical and operational limits, while also providing faster and more precise responses. In addition to more fully exploiting systems physical capabilities, this architecture provides for the independent and finely coordinated control of system variables-of-interest even when each effector affects all variables. A distinctive feature of this algorithm is that it can be implemented on state of the art controllers at update rates consistent with vehicle control.

Over the past few decades, advanced methods have been developed for the analysis of digital systems using mathematical reasoning, i.e., formal logic. These methods are supported by sophisticated software tools that can be used to perform analysis far beyond what is practically achievable using “paper and pencil” analysis. In December 2011, RTCA published RTCA DO-178C [1] along with a set of technical supplements including RTCA DO-333 [2] which provides guidance on the use of formal methods towards the certification of airborne software. Such methods have the potential to reduce the cost of verification by using formal analysis instead of conventional test-based methods to produce a portion of the verification evidence required for certification.

A Distributed Engine Control Working Group (DECWG) consisting of the Department of Defense (DoD), the National Aeronautics and Space Administration (NASA)- Glenn Research Center (GRC) and industry has been formed to examine the current and future requirements of propulsion engine systems. The scope of this study will include an assessment of the paradigm shift from centralized engine control architecture to an architecture based on distributed control utilizing open system standards. Included will be a description of the work begun in the 1990's, which continues today, followed by the identification of the remaining technical challenges which present barriers to on-engine distributed control.

In the present study, an experimental investigation was conducted to characterize a hot-air-based anti-/de-icing system for the icing protection of aero-engine inlet guide vanes(IGVs). The experimental study was conducted in a unique icing research tunnel available at Iowa State University (i.e., ISU-IRT). A hollowed IGV model embedded with U-shaped hot-air flowing conduit was designed and manufactured for the experimental investigations. During the experiments, while a high-speed imaging system was used to record the dynamic ice accretion or anti-/de-icing process over the surface of the IGV model for the test cases without and with the hot-air supply system being turned on, the corresponding surface temperature distributions on the IGV model were measured quantitatively by using a row of embedded thermocouples.

The global electric and hybrid aircraft market utilizing lithium-ion Energy Storage Systems (ESS) as a means of propulsion, is experiencing a period of extraordinary growth. We are witnessing the development of some of the most cutting-edge technology, and with that, some of the most complex challenges that we as an industry have ever faced. The primary challenge, and the most critical cause of concern, is a phenomenon known as a “Thermal Runaway”, in which the lithium-ion cell enters an uncontrollable, self-heating state, that if not contained, can propagate into a catastrophic fire in the aircraft. A Thermal Runaway (TR) can be caused by internal defects, damage, and/or abuse caused by an exceedance of its operational specifications, and it is a chemical reaction that cannot be stopped once the cell has reached its trigger temperature.