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This paper presents a PC based mathematical and rapid prototyping technique for anthropometric accommodation in a maintenance environment using the principle of simulation based design. The developed technique is capable of analyzing anthropometric data using multivariate (Principal component Analysis) approach to describe the body size variability of any given population. A number of body size representative cases are established which, when used properly within the constraints of the maintenance environments, will ensure the accommodation of a desired percentage of a population. This technique evaluates the percentage accommodation of a given population for the environment using the specific manikin cases as boundary conditions. In the case where any member of a maintenance crew cannot be accommodated, the technique has the capability of informing the designer of the environment why the member(s) is/are not accommodated.

The desire to operate rotorcraft in icing conditions has renewed the interest in developing high-fidelity analysis methods to predict ice accumulation and the ensuing rotor performance degradation. A subset of providing solutions for rotorcraft icing problems is predicting two-dimensional ice accumulation on rotor airfoils. While much has been done to predict ice for fixed-wing airfoil sections, the rotorcraft problem has two additional challenges: first, rotor airfoils tend to experience flows in higher Mach number regimes, often creating glaze ice which is harder to predict; second, rotor airfoils oscillate in pitch to produce balance across the rotor disk. A methodology and validation test cases are presented to solve the rotor airfoil problem as an important step to solving the larger rotorcraft icing problem. The process couples Navier-Stokes CFD analysis with the ice accretion analysis code, LEWICE3D.

Currently, the Aviation industry uses traditional methods of communication, coordination, & human interaction to give disposition to resolve any kind of nonconformance occurrences which occur during manufacturing or operation of commercial or defense products. This involves increased in-person interaction and additional travel, especially to address the nonconformance issues arising at supplier plants or airports around the globe. During Covid and post-Covid environments, human interactions for the transfer of detailed information at different & distant manufacturing plant locations has been difficult, since support engineering teams (Example: Liaison, Product Review, Quality, Supplier Quality, and Manufacturing Engineering, and/or Service Engineering) have been working remotely.

Orbital hole drilling technology has shown a great deal of promise for cost savings on applications in the aerospace industry where burr free, high quality holes are a necessity. This presentation will show some of the basic research on orbital drilling development Boeing is doing with the Advanced Manufacturing Research Center at Sheffield University and the deployment of the technology into production programs within The Boeing Company.

Since flight requirements often necessitate last-minute re-analysis, it became crucial to develop flexible and comprehensive transport phenomena analysis software that would quickly ensure all vehicle and payload requirements would be satisfied. The software would replace various mainframe-based software, such as the Thermal Radiation Analyzer System (TRASYS) and the Systems Improved Numerical Differencing Analyzer (SINDA). The software would need to have the flexibility to employ models that could be developed and modified as vehicle systems change. By use of event files which contain simple, intuitive commands, the characteristics of individual missions could be built as inputs to the model. By moving the Environmental Control & Life Support (ECLS) system model to the PC environment, each analyst would have execution, storage, and processing management control. And of course, software portability would be greatly increased.

The ISS U. S. ECLSS contains replaceable component designs to facilitate maintenance. A replaceable component is referred to as an Orbital Replacement Unit (ORU). Total U. S. ECLSS maintenance events that have occurred over the five years (2001-2005) of operations are summarized. A more detailed description is provided for the ECLSS Remove and Replace (R&R) maintenance activities that have occurred during the last two years and the associated logistics that supported these activities. Maintenance activities have replaced failed or degraded ORU's by Corrective Maintenance (CM) and replaced spent expendable ORU's by Preventative Maintenance (PM). Corrective maintenance is performed only when necessary and often on relatively short notice. Preventative maintenance is planned in advance and is normally performed at a specified ORU service time. The paper also describes activities and successful efforts to increase the expendable ORU service life.

This paper presents the results of development efforts relating to an advanced material processing technique, namely cryogenic milling, and its application to the processing of Al-7.5wt%Mg-0.2wt%N-20vol%SiC and Al 8wt%Ti-2wt%Ni nano-composite materials suitable for use in aerospace fastener applications. The effects of cryogenic milling in the material production are investigated via microstructural analysis. The advantages of cryogenic milling in the material production are presented with powder morphology and handling characteristics, and microstructural and nanostructural aspects. The resulting, very homogeneous material is discussed along with resulting mechanical properties, which are obtained through tension tests.

The Boeing Company is developing and implementing the tools for the 21st Century for product development with their Design Manufacturing and Producibility Simulation (DMAPS) program. DMAPS combines the best of people, hardware and software tools commercially available to develop product and process simulation applications. The DMAPS toolset enhances the process of preparing concept layouts, assembly layouts and build-to-packages. Comprised of an Integrated Product and Process Team (IPPT), DMAPS produces products faster and with higher quality. The result is a process that eliminates costly changes and rework, and provides all IPPT's the tools and training necessary to perform their tasks right the first time. Boeing applies DMAPS tools to a variety of existing and new programs to build more affordable products. Savings goals set forth by the program are shown in Figure 1.

This study covers CFD simulation of the air ventilation within the Assembly Complete stage of ISS on-orbit configuration of twelve modules. An assessment of ISS cabin aisle way airflow characteristics was performed on the basis of the integrated model computations. Both the quantitative evaluation of velocity distribution and qualitative analysis of three-dimensional airflow are presented.

This paper reports results of Computational Fluid Dynamics (CFD) analysis of carbon dioxide (CO2) gradient variations in twelve ISS modules. Computations were performed using two 3D integrated models: one from the U.S. Laboratory to the forward end, and the other from the U.S. Laboratory to the aft end of the ISS. Operation of the CO2 removal systems and CO2 generation among six International Space Station (ISS) crewmembers' metabolic processes were included in the model. For several crew location scenarios, a detailed analysis of the CO2 gradients and time evolution in zones potentially occupied by astronauts is presented. In general, the paper gives an extended example of the application of CFD analysis to complex problems related to the quality of the cabin air.

Proper design of the air ventilation system is critical to maintaining a healthy environment for the ISS crew. In this study, a computational fluid dynamic model was used to model the air circulation in Node 1 to identify the locations where there are low air velocities under nominal operating conditions and several reduced ventilation flow conditions. The reduced ventilation flow conditions analyzed were loss of cabin air fan, loss of inter-module ventilation from Node 1 to the US Lab, and loss of inter-module ventilation from the airlock to Node 1. For nominal operation of the ventilation system, about 5% of the node had air velocity of between 1 and 5 ft/min and 14% of the node had air velocity of between 5 and 10 ft/min. Loss of the cabin air fan and loss of Lab inter-module ventilation did not have a significant impact on the percentage of the node that would have low air circulation.

This CFD study is aimed at evaluation of the ventilation characteristics within the ISS Node 1 with the Advanced Resistive Exercise Device (ARED) protrusions into ECLS keep-out zones. An assessment of Node 1 airflow characteristics in the presence of the ARED and a human body simulation model has been performed for the current on-orbit configuration of the Node 1 ventilation system. Both the quantitative velocity distribution analysis and qualitative three-dimensional airflow evaluation have shown that the installation of the ARED in the Node 1 radial bay produces a minimal impact on the cabin ventilation characteristics and the crew.

This paper presents results of the CFD study aimed at evaluation of the CO2 concentration within the Shuttle Orbiter Middeck during the Launch on Need (LON) Crew Rescue flight. An assessment of the Middeck ventilation characteristics has been performed for two possible ventilation arrangements. A recommendation to use the ventilation system configuration with the open aft floor diffuser has been made on the basis of a three-dimensional airflow and CO2 gradient analysis.

ESA and NASA agencies agreed to run an interface compatibility test at the EADS facility between the Columbus flight module and a duplicate ground unit of a currently on-orbit US International Standard Payload Rack, the Human Research Facility (HRF) Flight Prototype Rack (FPR). The purpose of the test was to demonstrate the capability to run US payloads inside the European ISS module Columbus. One of the critical aspects to be verified to ensure suitable operations of the two systems was the combined performance of the hydraulic controls resident in the HRF and Columbus coolant loops. A hydraulic model of the HRF FPR was developed and combined with the Columbus Active Thermal Control System (ATCS) model. Several coupled thermal-hydraulic test cases were then performed, preceded by mathematical analysis, required to predict safe test conditions and to optimize the Columbus valve configurations.

Crew health is dependent on the concentration of carbon dioxide in the atmosphere breathed. Often, models used for concentration have used the assumption that each module of the space station is well mixed, i.e. that the CO2 concentration is constant throughout the module. In this paper, Computational Fluid Dynamics (CFD) modeling is used to assess and validate the accuracy of that assumption. The concentration of carbon dioxide as calculated by CFD was compared to the concentration as calculated by a lumped parameter model. The assumption that the module is well mixed allows the use of relatively simple models, which can be developed and run quickly in order to support decisions for on-orbit analysis. CFD models generate more detailed information, such as CO2 gradients within the modules and airflow and mixing characteristics. However, CFD models, particularly transient models, take longer to develop and use.

Ventilation characteristics of the Columbus module are numerically predicted on the basis of the Reynolds-Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) approaches. Effects of air supply diffuser modeling on computed flow are analyzed. An “effective diffuser” model that considerably reduces the number of computational cells for Columbus CFD ventilation analysis is proposed and tested. The computational models are verified by a comparison with the experimental data available. Special attention is paid to distinctions in fields of the time-averaged absolute velocity magnitude and the whole mean velocity that are due to the contribution of large-scale fluctuations. A technique to evaluate spatial distribution of the time-averaged absolute velocity magnitude using data of RANS steady-state predictions is suggested.

This paper addresses a simulation modeling case study of a batching process. The batching process exists in a multi-server, multi-queue aircraft component manufacturing system where all parts and batches are serial numbered for traceability. Every lot of parts requires a unique set of serial numbers and the sequence of batches is required to follow the airplane master production schedule. The study goal was to identify and provide solutions to shorten arrival time differences among parts going to the same batch in a system of more than 100 shared processes. Queue lengths, resource utilization, bottlenecks, and various scenario comparisons were yielded from simulation modeling exercises.

An automated system drills the outer moldline holes on a military aircraft wing. Currently, the operator manually checks countersink diameter every ten holes as a process quality check. The manual method of countersink inspection (using a countersink gauge with a dial readout) is prone to errors both in measurement and transcription, and is time consuming since the operator must stop the automated equipment before measuring the hole. Machine vision provides a fast, non-contact method for measuring countersink diameter, however, data from machine vision systems is frequently corrupted by non-gaussian noise which causes traditional model fitting methods, such as least squares, to fail miserably. We present a solution for circle measurement using a statistically robust fitting technique that does an exceptional job of identifying the countersink even in the presence of large amounts of structured and non-structured noise such as tear-out, scratches, surface defects, salt-and-pepper, etc.

One of the key elements of increasing the affordability of major weapons systems is reducing costs associated with manufacturing. Nondestructive evaluation (NDE) is a critical element of the manufacturing process and one that cannot be compromised. A key goal associated with NDE research and development is to help reduce the cost associated with quality assurance. In relation to composite structures, this is being approached from several directions, two of which will be discussed. The approach most frequently used for inspection of composite parts is to pull the parts out of the manufacturing cells and route them to a centralized quality assurance area for inspection. This approach leads to accumulation of non-recurring costs for tooling/fixturing to support the inspection and significant additions to production flow time. An alternative would be to develop nondestructive evaluation processes that can be performed in the manufacturing cells.

Electromagnetic forming (EMF) technology has been used lately for the joining and assembly of axisymmetric parts in the aerospace and automotive industries. A few case studies of compressive-type joining processes applied on both aluminum and titanium or stainless tubes for aerospace applications are presented. In the first case study, tests were conducted using 2024-T3 drawn tubes joined with a steel end fitting to form a torque tube using different forming variables including: the fitting geometry, material formability and forming power (KJ). The power setting and the fitting geometry were optimized to improve the fatigue life, torque off, and the axial load capability of the torque tube joints to drive the leading and trailing edge high-lift devices.