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Read more:  http://www.csir.co.za/enews/2015_Oct/16.html

 

The University of Pretoria is well advanced in a programme to experimentally validate numerical simulation software developed by the Council for Scientific and Industrial Research (CSIR) to accurately model the sloshing of fuel in an aircraft’s fuel tank. This was unveiled at a recent joint briefing at the university.

The project is taking place under the aegis of the Aerospace Industry Support Initiative of the Department of Trade and Industry. It involves Business Enterprises at the University of Pretoria (BEatUP), the CSIR and local aerospace company Denel Aerostructures (DAe).

The project’s origins lie in 2013, when the CSIR demonstrated software to simulate complex fluid motions to DAe. “DAe was very impressed with the potential of the software to predict fuel loading in aircraft fuel tanks,” noted retiring DAe designer Andries Visser. “The thing with software is [that] we need to validate what the software predicts in real life.”

“BEatUP was contracted by the CSIR,” reported BEatUP project and test engineer Jan Eksteen. “A laboratory was set up to simulate sloshing [in real life].”

“It was decided to fabricate two test tanks,” said Visser. “DAe’s job was firstly to design these tanks.” The first tank is cylindrical and is called the validation tank, which is 1 616 mm long and 635 mm in diameter. It is based on an external ferry tank for the Denel Rooivalk attack helicopter. This was used because Denel has the design authority for that tank. The second tank is rectangular in profile, with a length of 1 600 mm, a width of 600 mm and a height of 450 mm. Called the application tank, it is based on the fuel tank for an unmanned aerial vehicle.

The two tanks are mounted on test rigs. The test rig for the validation tank was specifically developed for the test programme. It can subject the tank to pitch rotation, longtitudinal motion (‘translation’, in engineering jargon) and vertical motion, and can do all of these actions simultaneously, if required. The tank was instrumented with three very sensitive seismic accelerometers and 14 high-precision pressure sensors, of laboratory quality and with a range of one bar each. It has an 18-channel data logging capability. The tests are performed and the outputs are measured. The data is then processed to get the required results.

The tests are done with three different water levels in the tank: low, half-full and high. They are also done at three frequencies and at others chosen at random. The first series of tests is being done without a baffle in the tank (a baffle reduces sloshing); these are now about 70% complete. They will be followed by a second series of tests, identical to the first, except that the tank will be fitted with a baffle. “This is not a research project,” highlighted CSIR aeronautical researcher Johan Heyns. “It’s so that we can improve industry.”

The CSIR used a number of open-source software libraries to develop its numerical simulation system. “We don’t want to reinvent the wheel,” he affirmed. “There’s a lot of software that has been developed. We wanted to use that.” The focus of the CSIR was on improving accuracy and increasing flexibility.

“It’s one thing to have nice [numerical] simulations. It’s another to have accurate results,” he pointed out. But the results of the validation process have been very encouraging. “There’s a very good correlation between the numerical [simulation] and experimental results. They’re almost too good! This is really encouraging.”

The numerical simulation is very accurate in its predictions of slosh wave frequency and amplitude. While it is less accurate with regard to pressure, it is far more accurate than any alternative system. “This tool allows us to provide engineers, within a week or two, with something that will improve their designs,” stressed Heyns. “This is a capability that will really enable South African industry. We can design safe systems [with this system]. “We don’t have to overdesign them. It really provides South African industry with a cost- effective solution.”

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Read more:  http://www.engineeringnews.co.za/article/efforts-under-way-to-validate-numerical-simulation-of-aircraft-fuel-behaviour-2015-12-11

In its aim to identify a business growth opportunity in the local aerospace industry, the Aerospace Industry Support Initiative (AISI), at the end of last year, assisted Cape Town-based machining and assembly company Daliff Precision Engineering in developing a mounting tray to support avionic components.

Avionics original-equipment manufacturer (OEM Tellumat, which manufactures trans-ponders and other avionics components for the aviation export market, will use the tray, says AISI programme manager Marié Botha.

“This initiative highlights that the Department of Trade and Industry (DTI), by using an existing State organ, the Council for Scientific and Industrial Research (CSIR), is bridging the gaps in the local aerospace industry,” she adds.

The AISI is a drive established in 2006 by the DTI and hosted and managed by the Pretoria-based CSIR.

The initiative, through the CSIR’s expertise and access to national infrastructure, “is responsible for the industrialisa-tion aim of the DTI to improve the competitiveness of the local aerospace industry”.

Import Substitution

The aim of the project between Daliff – a small, medium-sized and microenterprise (SMME) – and Tellumat, with assistance from the AISI, was for Daliff to design, manufacture and approve a mounting tray, which would also open potential export markets for the tray, explains Botha.

“Moreover, the intent of both parties is that Daliff, as Tellumat’s supply partner, will assume responsibility for the design and manufacture of the tray’s mechanical components.”

She further points out that the new mounting tray can be produced at a considerably lower cost, with shorter lead times, than an imported tray.

“Daliff’s design and production of a 3/8 mounting tray will now enable a full range, in different sizes, of mounting trays to be developed and marketed locally,” Botha says.

The project started in October 2014 and ended in March this year. Engineering included vibra-tion and structural testing of the tray to international standards and client specifications.

The project assisted in transferring technology from an OEM to an SMME; it also added to Daliff’s capabilities as an SMME. However, this also enabled Tellumat to enhance its supplier base.

“Without the AISI funding, this design and manufacturing project would not have been undertaken. “A small SMME, such as Daliff, cannot afford to take on risky design projects for which the payback period, until the product becomes established in the market place, which is envisaged to be years,” says Daliff chairperson Rowland Chute.

Focus Scope

The AISI is also involved in another project with South African aerospace integrator Aerosud, which focuses on the localised manufacturing of insulation blankets used in aircraft.

The blankets, made from natural fibres and composites, protect avionic components in the aircraft’s airframes against fluctuating temperatures.

As the manufacturer, Aerosud aims to create the capability, through technology and skills transfer, for local companies to manufacture the insulation blankets, thereby eliminating the need to import this product, explains Botha. “The company will focus on skills development and then consider the potential of transferring these skills to local SMMEs,” she adds.

The project started in April and is expected to end in March 2016.

Incentive Scheme

In addition to its focus on import substitutions, The AISI, in April, introduced a supplier development incent-ive scheme to incentivise key companies to beconme involved in local aerospace skills development and technology transfer.

The scheme will require aero-space integrators, such as Denel Aerostructures and Aerosud, to identify SMMEs that they would like to collaborate with, after which the AISI will offer an incentive to the integrators – a percentage of the increase in contract value between the SMME and the integrator.

The incentive is based on criteria that the SMMEs and the integrators have to comply with. These include, but are not limited to, broad-based black- economic-empowerment status, the percentage of women-owned and black-owned small busi-nesses and whether new manu-facturing or skills capabilities will be introduced.

“This is also in pursuit of government’s strategic objectives of transforming the industry,” concludes Botha.

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Read more:  http://www.engineeringnews.co.za/article/support-initiative-gaining-ground-boosting-supplier-development-2015-08-28