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Technical Paper

C919 Trailing Edge Assembly Interchangeable Tooling

2019-09-16
2019-01-1880
Traditional Trailing Edge (TE) assembly that utilise fixtures for accurate positioning of aircraft (a/c) parts do not allow for removal of specific tooling from the fixtures to travel with the TE, post assembly. Instead, the tooling that positions all the primary a/c assembly datums generally utilise precision pins of various sizes that index and clamp the a/c ribs. Often it is difficult to remove the pins post assembly before the spar can be taken out of the fixture. Use of hammers is common place to hit pins out of holes which is less than ideal considering the a/c parts can be fragile and the tooling is precision set. Also, the Main Assembly Fixture (MAJ) that will receive the TE will inevitably need to relocate some if not all the primary a/c ribs and therefore will most likely be subject to some amount of persuasion.
Technical Paper

Automation of Sorting and Kitting from cutting tables

2019-09-16
2019-01-1899
Within the current part production of carbon fiber parts a lot of manual work is included for sorting and kitting of automatic cut plies. This is required due to the high raw material costs and enables a good utilization of the materials. Automation of this non-value adding process will be a big benefit for the part production. The high variety of shapes and the different materials to be processed are complex boundary conditions, which are to be overcome. Broetje is in development of handling systems and automation solutions, which are used for a high variety of materials as well as for a high variety of shapes. These systems are meant to be an add-on for existing cutting tables as well as for fully integrated production systems with downstream automation equipment like draping hoods. Mayor challenges to overcome are safe gripping capabilities, detection of #non-cut fibers, high variety of shapes, complex logistic management. These challenges are addressed with Broetje’s ASK Solution.
Technical Paper

Analytical Model for Calibration Results performances enhancement, resulting in automated prescription for equipments

2019-09-16
2019-01-1878
The current aeronautical manufacturing sector is characterized by the high level of competence and the required requirement in its production processes, based on the objectives of profitability and safety (airworthiness). In recent years, there is a real revolution in the sector, where the most advanced tools for the organization and optimization of production are given priority, supported by the latest massively used techniques of automatic data collection. , their organized storage and their analytical classification. Metrology plays a key role in ensuring the quality and reliability of the information generated in these productive cycles. The provision of an analytical model of flexible measurement systems, capable and easily adaptable to the dynamics of the company, is presented as one of the pillars in which this new conception of production is based.
Technical Paper

An embedded simulation approach for tolerance analysis on vehicle propulsion subsystem

2019-08-15
2019-24-0079
An increasing demand for reducing cost and time effort of the design process via improved CAE (Computer-Aided Engineer) tools and methods has characterized the automotive industry over the past two decades. One of the main challenge regarded the effective simulation of a vehicle’s propulsion system dealing with different physical domains: several examples have been proposed in literature mainly based on co-simulation approach which involves a specific tool for each propulsion system part modeling. Nevertheless, these solutions are not fully suitable and effective to perform statistical analysis including all physical parameters. In this respect, this paper presents the definition and implementation of a new simulation methodology applied to a propulsion subsystem.
Technical Paper

A Penalization Method for 2D Ice Accretion Simulations

2019-06-10
2019-01-1939
Numerical tools for 3D in-flight icing simulations are not straightforward to automate when seeking robustness and quality of the results. Difficulties arise from the geometry and mesh updates which need to be treated with care to avoid folding of the geometry, negative volumes or poor mesh quality. This paper aims at solving the mesh update issue by avoiding the re-meshing of the iced geometry. An immersed boundary method (here, penalization) is applied to a 2D ice accretion suite for multi-step icing simulations. The suggested approach starts from a standard body-fitted mesh, thus keeping the same solution for the first icing layer. Then, instead of updating the mesh, a penalization method is applied including: the detection of the immersed boundary, the penalization of the volume solvers to impose the boundary condition and the extraction of the surface data from the field solution.
Technical Paper

Numerical Simulation of Aircraft and Variable-Pitch Propeller Icing with Explicit Coupling

2019-06-10
2019-01-1954
A 3D CFD methodology is presented to simulate ice build-up on propeller blades exposed to known icing conditions in flight, with automatic blade pitch variation at constant RPM to maintain the desired thrust. One blade of a six-blade propeller and a 70-passenger twin-engine turboprop are analyzed as stand-alone components in a multi-shot quasi-steady icing simulation. The thrust that must be generated by the propellers is obtained from the drag computed on the aircraft. The flight conditions are typical for a 70-passenger twin-engine turboprop in a holding pattern in Appendix C icing conditions: 190 kts at an altitude of 6,000 ft. The rotation rate remains constant at 850 rpm, a typical operating condition for this flight envelope.
Technical Paper

Type IV Anti-Icing Fluid Subjected to Light Freezing Rain: Visual and Thermal Analysis

2019-06-10
2019-01-1971
Deicing the aircraft using fluid, prior takeoff is mandatory; since a thin layer of ice or snow can compromise the safety. With the same idea, to use anti-icing fluid during a frozen precipitation to protect the aircraft is also essential. Commercialized anti-icing fluids all pass the process of qualification as described in the SAE documents. One of these documents specifies a set of tests that reproduce freezing precipitation to obtain endurance time and then the holdover timetables. The endurance time is determined by visual inspection: when 30% of the plate is covered with frozen contaminants. With the evolution of technology and the venue of new tools, it may simplify the process, and at least confirm the observations. This paper proposed a thermal and visual analysis of the behavior of a Type IV fluid subjected to light freezing rain. During the precipitation, the plate temperature is measured with thermocouples and recorded using a visual camera and an IR camera.
Technical Paper

Experimental Aerodynamic Simulation of Glaze Ice Accretion on a Swept Wing

2019-06-10
2019-01-1987
Aerodynamic assessment of icing effects on swept wings is an important component of a larger effort to improve three-dimensional icing simulation capabilities. An understanding of ice-shape geometric fidelity and Reynolds and Mach number effects on iced-wing aerodynamics is needed to guide the development and validation of ice-accretion simulation tools. To this end, wind-tunnel testing was carried out for 8.9% and 13.3% scale semispan wing models based upon the Common Research Model airplane configuration. Various levels of geometric fidelity of an artificial ice shape representing a realistic glaze-ice accretion on a swept wing were investigated. The highest fidelity artificial ice shape reproduced all of the three-dimensional features associated with the glaze ice accretion. The lowest fidelity artificial ice shapes were simple, spanwise-varying horn ice geometries intended to represent the maximum ice thickness on the wing upper surface.
Technical Paper

Runway Deicing Product Anti/Deicing Performance Assessment: Review and Future Directions

2019-06-10
2019-01-1974
Every winter, northern airport operations are disrupted by heavy snowstorms and freezing precipitations. A simple snow accumulation or a thin layer of ice can affect aircraft operations (take-off, landing and taxi), and increase the risk for passengers and crew members, by rendering the runway slippery. Any deficits in deicing operations can also lead to flight delays and even cancellations that cost a lot to the industry. In order to maintain the runway and taxiway in a safe and useable condition, airport authorities use mechanical tools, but also chemical products. Chemical products available on the market for use in airports are principally in solid forms and liquid form, and are denominated as Runway Deicing Product (RDP).
Technical Paper

Experimental and Computer Model Results for a Carbon Nanotubes Electrothermal De-Icing System

2019-06-10
2019-01-2005
Results from a three-dimensional computer model of a Carbon Nanotubes (CNT) based de-icing system are compared to experimental data obtained at COLLINS-Ohio Icing Wind Tunnel (IWT). The experiments were performed using a prototype of a CNT based de-icing system installed in a section of a business jet horizontal tail. The 3D numerical analysis tools used in the comparisons are AIPAC [1] and CFD++. The former was derived from HASPAC, an anti-icing computer model developed at Wichita State University in 2010 [3, 9, 10]. AIPAC uses the finite volumes method for the solution of the icing problem on an airfoil leading edge (or other 3D surfaces) and relies on any CFD solver to obtain the external flow properties used as boundary conditions. AIPAC is capable of predicting 3D multi-step ice shapes under rime, glaze and mixed regimes, and can also deal with the complex dynamics of cyclic ice accretion, melting, and shedding present in the realm of aircraft electrothermal de-icing systems.
Technical Paper

Event-Driven Simulation of Particle-Particle and Particle-Surface Collisions in Ice Crystal Icing

2019-06-10
2019-01-2014
This paper describes an event-driven simulation tool for predicting particle-particle and particle-surface interactions in ice crystal icing (ICI). A new accretion model which is much less empirical than existing models for predicting ICI accretion is also described. Unlike previous models, the new “gouge/bounce model” (GBM) differentiates between (erosion) losses resulting from particle bounce and those resulting from particle gouging. A bounce threshold based on the tangential Stokes number is used to calculate most of the bounce loss. The GBM also predicts ejecta velocities and directions, at least approximately, which is important because most of the mixed-phase mass flux impacting a surface actually bounces off or erodes existing material in ICI, thereby increasing the mass flux downstream.
Technical Paper

Design and Validation of Low-Cost Intensity Probe

2019-06-05
2019-01-1462
Sound intensity measurement techniques that used a two-microphone configuration, were first developed in the late 1970s. Originally, the focus was on improving precision during testing or post-processing. However, with the advent of modern, sophisticated equipment, the focus has shifted to the apparatus. Availability of phase-matched microphones has made post-test correction obsolete as the microphones eliminate a majority of the errors before the data is even collected. This accuracy, however, comes at a cost, as phase-matched microphones are highly priced. This paper discusses employing the method of improving post-processing precision, using inexpensive, current equipment. The phase error of the system is corrected using a simple calibration technique and a handheld phase calibrator that is similar to the one used for amplitude calibration of microphones.
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