Bombardier (United Kingdom)

Due to the vast distances between aerospace supply chain (SC) members, the logistical implications of outsourcing decisions must be considered, including the uncertainty in transportation costs (TC) caused by fluctuating fuel prices. Analytical models often model the impact of fuel prices without capturing the dynamic behavior of SC networks. Discrete event simulation (DES) can capture such behavior and correlate it with financial performance to support decision making. This paper uses DES to model the impact of fuel prices on TC and inventory holding costs (IHC) in a three-tier SC scenario where suppliers deliver products via land/sea- or air freight. The results show the transportation decisions can be used to mitigate the influence of fuel prices on the TC. The value, weight and size of products transported throughout the SC also influence in whether TCs or IHCs drive total SC costs. Future work could apply the methodology to larger and more complex SCs.

Abstract The chapter presents the utilization of digital manufacture with a value‐driven Manufacture context, including the development of digital manufacturing capability for integration into the Integrated Product Process Development process. As part of the business process the key phase being addressed is the concurrent integration of manufacturing requirements at the stage when design geometry has been released. The digital manufacturing platform is used to provide simulations of the assembly process that have been developed in order provide simultaneous estimation of the associated learning curves, cycle time, recurring cost, and throughput. The integration of Lean principles at the program and functional levels will also be addressed as the Lean approach underwrites the entire program. Fundamentally, the compression of lead time, increase in value‐added effort, and reduction in waste and inefficiency are the key Lean challenges being addressed. Consequently, a Lean Implementation Methodology will be presented while the Lean characteristics of the functional development will also be highlighted. The latter also includes the Lean Flow Accounting Methodology that addresses the Lean flow of work through a plant in order to maximize value‐added effort according to a top‐down assessment of financial value and optimal throughput, thereby reducing Work In Progress.

The shielding effectiveness of two woven carbon fiber composite (CFC) materials is reported. Theoretical calculations using plane wave shielding theory and Effective Medium Theory provide the same shielding level due to the fact that there is significant fiber running parallel to the incident electric field vector. Measurements of shielding effectiveness on 1.14 mm samples at X-band and S-band show the composites provide at least 70 dB of shielding across X-band and at least 85 dB of shielding across S-band. Return-loss and reflection coefficient measurements confirm that reflection is the predominant shielding mechanism with little absorption occurring due to the high carbon content (50.5 % by volume) leading to the creation of many connected paths of fiber throughout the composites. In addition, measurements were performed at S-band on a reduced thickness sample (0.66 mm) of one of the composites. This was shown to provide 70 dB of shielding across the frequency band. This was below the level expected but could be explained by the reduction in contact between the sample and the sample holder.

The shielding effectiveness of two woven carbon fibre composite (CFC) materials has been calculated using plane wave shielding theory and effective medium theory. Both methods provide the same shielding result. Measurements of the shielding effectiveness using an X-band waveguide show similar levels of shielding to that of aluminium. The high shielding level is due to the large concentration of carbon in both composite samples (50.5%).

Some critical avionic systems require cooling air via vents on the side of the aircraft, thus creating leakage points for high-intensity electromagnetic radiation. This paper presents a novel application of high-intensity radiated field (HIRF) shielding using a rectangular waveguide array, while maintaining cooling airflow requirements. Signal attenuation versus frequency and depth of the array has been calculated using closed-form equations. The simulation and measurement results are in good agreement with the calculated values. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 44: 130–132, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20566

The attenuation/transmission characteristics and hence High Intensity Radiated Field (HIRF) immunity of a jet engine nacelle air vent, called a NACA Scoop, are reported. For the first time, results from simulations using a TLM based solver and measurements of the NACA Scoop in an anechoic chamber are discussed and compared.