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The effects of trailing edge blowing on aerodynamic characteristics of the NACA 0012 airfoil and optimization of the blowing slot geometry

Yousefi K., Saleh R.

Journal of Theoretical and Applied Mechanics

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2014

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Vol. 52 nr 1

165--179

EN

The effects of blowing and its parameters including the jet amplitude, blowing coefficient and jet width in order to flow control was evaluated for a NACA 0012 airfoil. The flow was considered as fully turbulent with the Reynolds number of 5 · 105, and the Menter shear stress turbulent model was employed. Tangential and perpendicular blowing at the trailing edge were applied on the airfoil upper surface, and the jet widths were varied from 1.5 to 4 percent of the chord length, and the jet amplitude was also selected 0.1, 0.3 and 0.5. In the tangential blowing, the results showed that when the blowing amplitude increases, the lift- to-drag ratio rises by 15 percent, however, the smaller amounts of the blowing amplitude are more effective in the perpendicular blowing. Furthermore, when the blowing jet width rises, the lift-to-drag ratio increases continuously in the tangential blowing and decreases quasi- linear in the perpendicular blowing. In this study, the blowing jet width 3.5 and 4 percent of the chord length for the tangential blowing was selected as optimal values as well as smaller amounts of blowing jet width are more suitable for the perpendicular blowing. Finally, the lift-to-drag ratio was increased by 17 percent for the tangential blowing in the angle of attack of 18 degrees.

2

Computer simulation of temperature distribution on a solid target for 201Tl production

Aboudzadeh Rovais M. R., Yousefi K., Ardaneh K., Mirzaii M.

Nukleonika

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2011

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Vol. 56, No. 4

283-289

EN

Thallium-201 is of great interest in nuclear medicine for diagnostic purposes. It is produced by the 203Tl(p,3n)201Pb nuclear reaction. Since the target for 201Tl production is a solid target and the maximum beam current for the irradiation has a direct relation with its temperature surface, therefore, the control of temperature during the irradiation is essential. Designing a proper cooling system is one of the important and determining parameters in radionuclide production efficiency. Non-controlled temperature would cause melting and consequently loss of target materials that could be very costly especially when an isotopically enriched material is used. In this study, the heat transfer and temperature distribution on the target has been simulated based on a computational fluid dynamics (CDF) code for the thermal behavior of the target during the irradiation and under the different beam currents, cooling flow rates and target designing. The results on the routinely used target for the production of 201Tl in AMIRS, showed that there was a good linearity between proton beam currents (in the range of 100–350 mi A) and maximum temperature on the thallium target (345–458 K). The results also showed that the flow rate of the cooling water can be brought down (from routinely used 45 L/min) to 15 L/min without any risk of melting of target material.

3

Design and manufacture of krypton gas target for 81Rb production at a 30 MeV cyclotron

Rovais M.R.A., Mirzaii M., Kiyomarsi M., Yousefi K., Shadanpour N., Ensaf M. R.

Nukleonika

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2010

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Vol. 55, No. 2

225-231

EN

The cyclotron of nuclear medicine research group at the Agricultural, Medical and Industrial Research School (AMIRS) has been producing several radionuclides such as 201Tl, 67Ga, 18F and 81Rb for nuclear medicine centers. Gas targets are utilized in a variety of cyclotron producing radionuclides which are used in nuclear medicine centers. We report a method for the design and manufacture of a cyclotron gas target which facilitates both the collection and processing of the krypton gas target as well as the desired 81Rb. In this study a gas target was designed for routine production of 81Rb (for a 81Rb/81mKr generator) through the nuclear reaction natKr(p,2n)81Rb → 81mKr. The incident energy of protons on the target was 26.5 MeV. The gas target was made of stainless steel. The length of the target was 251 mm with double titanium windows, 20 μm in thickness. A production yield of 3.18±0.27 mCi/μA·h was obtained which was more than 80% of the calculated yield (4.1 mCi/μA·h).