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Design and manufacturing engineers engaged in the conceptual and detail design stages of an aircraft have an ever increases number of tools and resources. However, these tools deal mainly with the physical structure and properties of the aircraft. Recently an increased effort has been made to take into account the producibil-ity and cost of an aircraft during the design phase. One of the tools being used by Lockheed Martin Tactical Aircraft Systems to accomplish this is Discrete Event Simulation. This form of simulation models dynamic production, information, and material flows. It enables an engineer to have greater visibility into the effects that he/ she makes on the overall aircraft production system. Machines and processes with different cost, speed, quality, and maintenance properties can be analyzed with respect to the system to justify their inclusion.

This paper describes a joint SAE automotive and aerospace Recommended Practice SAE J3168 now in development to standardize a process for Reliability Physics Analysis. This is a science-based approach to implement Physics-of-Failure research in conducting durability simulations in a Computer Aided Engineering Environment. It is used to calculate failure mechanism susceptibilities and estimate the likelihood of failure and the expected durability life of Electrical, Electronic and Electromechanical components and equipment, due to stresses such as mechanical shock, vibration, temperature cycling, etc. Reliability Physics Analysis is based on the material science principle of stress driven damage accumulation in materials. The process enables the identification of potential failure risks early in the design phase so that such risks can be designed out in order to efficiently design high reliable and robustness into electronic products.

MIT Lincoln Laboratory is tasked by the U.S. Federal Aviation Administration to investigate the use of the NEXRAD polarimetric radars* for the remote sensing of icing conditions hazardous to aircraft. A critical aspect of the investigation concerns validation that has relied upon commercial airline icing pilot reports and a dedicated campaign of in situ flights in winter storms. During the month of February in 2012 and 2013, the Convair-580 aircraft operated by the National Research Council of Canada was used for in situ validation of snowstorm characteristics under simultaneous observation by NEXRAD radars in Cleveland, Ohio and Buffalo, New York. The most anisotropic and easily distinguished winter targets to dual pol radar are ice crystals.

We report on a feasibility study of an optical micro-electro-mechanical systems (MEMS) flow sensor to measure flow rate using Moiré fringe displacement of a floating element. Due to constraints on weight, power, and size for space environmental systems, the development of sensor components that minimize the equivalent systems mass (ESM) while maintaining or exceeding required specifications is highly desirable. A feature of the optical detection method is a physical separation of electrical components from the flow stream. The geometric Moiré fringe shift optically amplifies small displacements by the ratio of the fringe pitch to the movable grating pitch that is detected using an external CCD imager, providing an electrically isolated, robust, direct scheme for detecting flow from shear stress induced displacement.

The advent of turbochargers and the Eco-Boost technology at Ford in gasoline engines creates new challenges that need to be addressed with innovative designs. One of them is flow induced noise caused by airflow entering the turbocharger during off design operation. At certain vehicle operation conditions, the mass flow rate and pressure ratio are such that compressor wheel can generate a wide range of acoustic frequencies. Characterization of ‘whistles’ or pure tonal noises, ‘whoosh’ or broad band frequency noise caused by flow separation from the blade surfaces, and chirps, where the frequency increases or decreases with time are a few of the common error states. Understanding the fundamental mechanisms of such noise generation is necessary for developing effective countermeasures for the noise source generation. Computational Aero-Acoustic (CAA) analyses are performed to study the effects of inlet and outlet conditions to find the source of the noise.

The airflow that enters the front grille of a ground vehicle for the purpose of component cooling has a significant effect on aerodynamic drag (engine airflow drag). Furthermore, engine airflow is known to be capable of influencing upstream external airflow (interference drag). The combined effect of these phenomena is commonly referred to as cooling drag, which generally contributes up to 10% of total vehicle drag. Due to this coupled nature, cooling drag is difficult to understand as it contains influences from multiple locations around the vehicle. A good understanding of the sources of cooling drag is paramount to drive vehicle design to a low cooling drag configuration. In this work, a production level Lincoln MKZ was modified so that a number of variables could be tested in both static ground and moving ground wind tunnel conditions. All tests were conducted at 80 MPH.

In an engine system, the piston pin is subjected to high loading and severe lubrication conditions, and pin seizures still occur during new engine development. A better understanding of the lubricating oil behavior and the dynamics of the piston pin could lead to cost- effective solutions to mitigate these problems. However, research in this area is still limited due to the complexity of the lubrication and the pin dynamics. In this work, a numerical model that considers structure deformation and oil cavitation was developed to investigate the lubrication and dynamics of the piston pin. The model combines multi-body dynamics and elasto-hydrodynamic lubrication. A routine was established for generating and processing compliance matrices and further optimized to reduce computation time and improve the convergence of the equations. A simple built-in wear model was used to modify the pin bore and small end profiles based on the asperity contact pressures.