Dual-solver hybrid computational approaches for design and analysis of vertical lift vehicles

2021 ◽  
pp. 1-22
Author(s):  
M.J. Smith ◽  
A. Moushegian

Abstract The cost of Reynolds-Averaged Navier-Stokes simulations can be restrictive to implement in aeromechanics design and analysis of vertical lift configurations given the cost to resolve the flow on a mesh sufficient to provide accurate aerodynamic and structural loads. Dual-solver hybrid methods have been developed that resolve the configuration and the near field with the Reynolds-Averaged Navier-Stokes solvers, while the wake is resolved with vorticity-preserving methods that are more cost-effective. These dual-solver approaches can be integrated into an organisation’s workflow to bridge the gap between lower-fidelity methods and the expensive Reynolds-Averaged Navier-Stokes when there are complex physics present. This paper provides an overview of different dual-solver hybrid methods, coupling approaches, and future efforts to expand their capabilities in the areas of novel configurations and operations in constrained and turbulent environments.

2016 ◽  
Vol 2016 (DPC) ◽  
pp. 002152-002181 ◽  
Author(s):  
Nozad Karim ◽  
Rong Zhou ◽  
Jun Fan

High-speed digital and wireless devices radiate undesired electromagnetic noises that affect the normal operation of other devices causing electromagnetic interference (EMI) problems. Printed circuit board (PCB) and system-level shielding may alleviate inter-system EMI between the PCB board and the outside environment, but does not prevent intra-system EMI within the shielding enclosure. Package and System in Package (SiP) level shielding is often used to minimize intra-system EMI issues. An external metal lid is traditionally employed to prevent noise emission from a device, but the cost and size of this technique makes it unattractive for modern electronics. Conformal shielding is gaining momentum due to its size and height advantages. However, high cost and complexity of the sprayed coating shield prevents it from being used for a wide range of low cost commercial applications. In this paper, an innovative shielding technology with sputtered metal conformal shield is investigated using a specially designed test vehicle. By sputtering a conductive material onto a package, a very thin (typically a few μm) metal layer is constructed on the top and around four sides of the package. This thin sputtered metal layer adds virtually zero penalty to the package size. The cost and complexity of the sputtering process is significantly lower compared to a spraying process. Several types of shielded and unshielded modules were built and extensively tested for both far-field and near-field shielding effectiveness (SE) in a semi-anechoic chamber. The performance of the sputtered conformal shield is compared to that of an unshielded module and the sprayed shield. The measured results show that the sputtered shield performs equally well to a sprayed shield, in far field test, with most measurements better than 40 dB of SE. In near field testing, sputtered shields mostly outperform the sprayed shield, especially when compared in the entire scanned region. A well-designed sputtered conformal shield can, therefore, be a very cost-effective EMI solution for a wide range of packages, such as SiP. Also in the paper, a full wave 3D HFSS model is presented and simulated results for both far and near field are compared with measured data.


Author(s):  
James F. Mancuso

IBM PC compatible computers are widely used in microscopy for applications ranging from control to image acquisition and analysis. The choice of IBM-PC based systems over competing computer platforms can be based on technical merit alone or on a number of factors relating to economics, availability of peripherals, management dictum, or simple personal preference.IBM-PC got a strong “head start” by first dominating clerical, document processing and financial applications. The use of these computers spilled into the laboratory where the DOS based IBM-PC replaced mini-computers. Compared to minicomputer, the PC provided a more for cost-effective platform for applications in numerical analysis, engineering and design, instrument control, image acquisition and image processing. In addition, the sitewide use of a common PC platform could reduce the cost of training and support services relative to cases where many different computer platforms were used. This could be especially true for the microscopists who must use computers in both the laboratory and the office.


Phlebologie ◽  
2007 ◽  
Vol 36 (06) ◽  
pp. 309-312 ◽  
Author(s):  
T. Schulz ◽  
M. Jünger ◽  
M. Hahn

Summary Objective: The goal of the study was to assess the effectiveness and patient tolerability of single-session, sonographically guided, transcatheter foam sclerotherapy and to evaluate its economic impact. Patients, methods: We treated 20 patients with a total of 22 varicoses of the great saphenous vein (GSV) in Hach stage III-IV, clinical stage C2-C5 and a mean GSV diameter of 9 mm (range: 7 to 13 mm). We used 10 ml 3% Aethoxysklerol®. Additional varicoses of the auxiliary veins of the GSV were sclerosed immediately afterwards. Results: The occlusion rate in the treated GSVs was 100% one week after therapy as demonstrated with duplex sonography. The cost of the procedure was 207.91 E including follow-up visit, with an average loss of working time of 0.6 days. After one year one patient showed clinical signs of recurrent varicosis in the GSV; duplex sonography showed reflux in the region of the saphenofemoral junction in a total of seven patients (32% of the treated GSVs). Conclusion: Transcatheter foam sclerotherapy of the GSV is a cost-effective, safe method of treating varicoses of GSV and broadens the spectrum of therapeutic options. Relapses can be re-treated inexpensively with sclerotherapy.


2019 ◽  
Vol 2 (4) ◽  
pp. 260-266
Author(s):  
Haru Purnomo Ipung ◽  
Amin Soetomo

This research proposed a model to assist the design of the associated data architecture and data analytic to support talent forecast in the current accelerating changes in economy, industry and business change due to the accelerating pace of technological change. The emerging and re-emerging economy model were available, such as Industrial revolution 4.0, platform economy, sharing economy and token economy. Those were driven by new business model and technology innovation. An increase capability of technology to automate more jobs will cause a shift in talent pool and workforce. New business model emerge as the availabilityand the cost effective emerging technology, and as a result of emerging or re-emerging economic models. Both, new business model and technology innovation, create new jobs and works that have not been existed decades ago. The future workers will be faced by jobs that may not exist today. A dynamics model of inter-correlation of economy, industry, business model and talent forecast were proposed. A collection of literature review were conducted to initially validate the model.


The choice of cost-effective method of anticorrosive protection of steel structures is an urgent and time consuming task, considering the significant number of protection ways, differing from each other in the complex of technological, physical, chemical and economic characteristics. To reduce the complexity of solving this problem, the author proposes a computational tool that can be considered as a subsystem of computer-aided design and used at the stage of variant and detailed design of steel structures. As a criterion of the effectiveness of the anti-corrosion protection method, the cost of the protective coating during the service life is accepted. The analysis of existing methods of steel protection against corrosion is performed, the possibility of their use for the protection of the most common steel structures is established, as well as the estimated period of effective operation of the coating. The developed computational tool makes it possible to choose the best method of protection of steel structures against corrosion, taking into account the operating conditions of the protected structure and the possibility of using a protective coating.


Author(s):  
W. C. Solomon ◽  
M. T. Lilly ◽  
J. I. Sodiki

The development and evaluation of brake pads using groundnut shell (GS) particles as substitute material for asbestos were carried out in this study. This was with a view to harnessing the properties of GS, which is largely deposited as waste, and in replacing asbestos which is carcinogenic in nature despite its good tribological and mechanical properties. Two sets of composite material were developed using varying particle sizes of GS as filler material, with phenolic resin as binder with percentage compositions of 45% and 50% respectively. Results obtained indicate that the compressive strength and density increase as the sieve size of the filler material decreases, while water and oil absorption rates increase with an increase in sieve size of GS particle. This study also indicates that the cost of producing brake pad can be reduced by 19.14 percent if GS is use as filler material in producing brake pad. The results when compared with those of asbestos and industrial waste showed that GS particle can be used as an effective replacement for asbestos in producing automobile brake pad. Unlike asbestos, GS-based brake pads are environmental friendly, biodegradable and cost effective.


2019 ◽  
Vol 2019 (4) ◽  
pp. 7-22
Author(s):  
Georges Bridel ◽  
Zdobyslaw Goraj ◽  
Lukasz Kiszkowiak ◽  
Jean-Georges Brévot ◽  
Jean-Pierre Devaux ◽  
...  

Abstract Advanced jet training still relies on old concepts and solutions that are no longer efficient when considering the current and forthcoming changes in air combat. The cost of those old solutions to develop and maintain combat pilot skills are important, adding even more constraints to the training limitations. The requirement of having a trainer aircraft able to perform also light combat aircraft operational mission is adding unnecessary complexity and cost without any real operational advantages to air combat mission training. Thanks to emerging technologies, the JANUS project will study the feasibility of a brand-new concept of agile manoeuvrable training aircraft and an integrated training system, able to provide a live, virtual and constructive environment. The JANUS concept is based on a lightweight, low-cost, high energy aircraft associated to a ground based Integrated Training System providing simulated and emulated signals, simulated and real opponents, combined with real-time feedback on pilot’s physiological characteristics: traditionally embedded sensors are replaced with emulated signals, simulated opponents are proposed to the pilot, enabling out of sight engagement. JANUS is also providing new cost effective and more realistic solutions for “Red air aircraft” missions, organised in so-called “Aggressor Squadrons”.


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