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Nanofluids have emerged as potential prospect coolant in heat transfer applications. Hybrid nanofluid is the is the recently developed class of nanofluids having two different types of nanoparticles suspended in the base fluid. In this research, a novel hybrid nanofluid containing Fe2O3-TiO2 (50:50) nanoparticles suspended in water basefluid has been used to improve the convective heat transfer in aluminum tube automotive radiator. Three hybrid nanoparticle concentrations (0.005 vol.%, 0.007 vol.% and 0.009 vol.%) were tested. Effect of inlet temperature and fluid velocity on heat transfer rate was examined by varying the inlet temperature from 48 °C to 56 °C and flowrate from 11 LPM to 15 LPM. Heat transfer rate increased by a maximum of 26.7% at 56 °C inlet temperature, 15 LPM flowrate and 0.009 vol.% nanoparticle concentration. At aforementioned operating conditions, Nusselt number increased by 20.03%. Increase in inlet temperature from 48 °C to 56 °C increased the heat transfer rate by 8%. Past 0.009 vol.% concentration, nanoparticle clogging diminished the stability of hybrid nanofluid which results in overall performance deterioration.

In this study, a novel crash box idea was presented, including a step-by-step collapsible structure by joining coaxial tubes with gradual bonding surface areas. This telescopic crash box absorbed impact energy by sequentially fracturing the adhesive interfaces from the top tube to the back tubes. In each bonding interface fracture, a certain amount of the impact energy was reduced. These gradually broken adhesive bonds and subsequent movement of the coaxial tubes were increased pedestrian safety by producing fewer impact forces and adding more braking time. Due to the just adhesive joints break after small hits, a broken crash box can be repaired easily by bonding coaxial tubes. Validation of the design was performed using the Finite Element Simulations by parametric modelling of the representative design of crash boxes with frontal impact simulations of a vehicle. Transmitted forces to the vehicle body were obtained according to impact duration. Impact energies were obtained by calculating the area under impact of force–displacement curves. The optimal size of the coaxial tube bonding interfaces and the number of the telescopic tubes were obtained for maximum energy absorption comparing with conventional crash boxes.

Tubular products have very important applications in various areas especially in the transportation industries. For instance, in the structure of cars there are various tubular products like roof headers, engine cradles, roof rails and frame rails with complex geometries which most of them need multiple steps like tube drawing, tube bending and hydroforming for their production. Based on the recent studies by this group, it was proven that in most of the structural tubular parts in the cars it was not necessary to have constant thickness along the axial direction of tube and it will be considered as overdesign and the overall weight of structures can be reduced considerably by using variable thickness tubes. In this paper, the variable thickness tube drawing and its applications in the tube bending and hydroforming applications were studied. The results showed that this process can have important role in reduction of defective parts in the production of complex tubes by the tube hydroforming method. However especial considerations should be taken into account in the design of thickness distribution along axial direction of these kinds of tubes to avoid problems in the drawing step and as well in the bending and hydroforming steps., 5th International Light Metals Technology Conference 2011 (LMT 2011). Lüneburg, Germany. July 19-22, 2011, Series: Material Science Forum; no. 690

To study the impact of different semi-solid dosage form components on the leaching of Bisphenol A (BPA) and Bisphenol A diglycidyl ether (BADGE) from the epoxy resin-based inner lacquer of aluminium tubes, the tubes were filled with different matrix preparations and stored at an elevated temperature. Despite compliance with the European Standards EN 15348 and EN 15766 on porosity and polymerisation of internal coatings of aluminium tubes, the commercially available tubes used in the study contained an increased amount of polymerisation residues, such as unbound BPA, BADGE and BADGE derivatives in the lacquer, as determined by acetonitrile extraction. Storage of Macrogol ointments in these tubes resulted in an almost quantitative migration of the unbound polymerisation residues from the coating into the ointment. In addition, due to alterations observed in the RP-HPLC chromatograms of the matrix spiked with BADGE and BADGE derivatives it is supposed that the leachates can react with formulation components. The contamination of the medicinal product by BPA, BADGE and BADGE derivatives can be precluded by using aluminium tubes with an internal lacquer with a low degree of unbound polymerisation residues.

Results of an experimental and numerical study on rib reinforced square cross-section thin wall extruded aluminium tubes formed by TIG welding process subjected to axial compression are presented in this paper. The distance between the ribs plays a vital role in modifying the energy absorption capacity of structure. Ribs assist the formation of more number of plastic hinges. As the rate of loading increases, the mean crushing force and energy absorption also increases for the same axial crushing distance. Results of the numerical study were found to be within 5-8% variation with the experimental results. Copyright � 2014 Inderscience Enterprises Ltd.

A new method for determination of formability limit in the tube drawing process was developed using the position controlled mandrel technique. In this method the mandrel has conical angle in a way that with change of mandrel position, the distance between die and mandrel will be changed and various combinations of thicknesses can be obtained using just one conic mandrel. The advantage of this method is determining the limit cross-sectional reduction for each tube dimension with just one experiment. The realized drawing limit tests on the aluminium tubes show that the average maximum area reduction of AA6063 tubes is about 40%. An optimal tube drawing schedule for production of the constant wall thickness aluminium tubes with high cross-sectional reduction in one pass was successfully established based on the proposed formability limit test., TMS 2011 Annual Meeting & Exhibition, San Diego, California, USA, February 27 - March 3, 2011

The influence of temperature and applied lacquer on aluminium (Al) tubes on physico- chemical changes of tomato paste during storage was studied. Packaging and storage conditions have a considerable influence on both the oxidative changes in the product and corrosion behaviour of the Al tubes. The greatest changes during storage were the ascorbic acid and hydroxymethylfurfural contents ; the compounds known to possess certain oxido-reduction power. The consequence of oxidation-reduction reactions taking place during storage was the establishment of particular redox values: the lower the reducing power of the compounds present, the higher the rH value obtained.

Cork is a complex natural cellular material with quite unknown or not well understood properties. It is available in the natural and in the agglomerate form and it is an ecological and very durable material. That is why it is used today as thermal and acoustic insulator, as a seal and as an energy-absorbing medium in flooring, shoes and packaging, among others. However, the application of agglomerate cork as filler inside structural thin-walled sections, in order to increase the energy absorption, has not been much explored. Dynamic experimental tests were carried out on empty and micro-agglomerate cork-filled tubes with 22 and 50 mm in internal diameter (D) and length (L), respectively, and numerical simulations were performed with the finite element method software LS-DYNATM, showing good agreement in terms of load-displacement curves and deformation patterns. Having validated the numerical model with experiments, the finite element model was used to undertake a systematic study of circular tubular structures impacted at 10 m/s. The load-deformation characteristics, energy-absorption response and collapse mode transitions of empty and cork-filled aluminium tubes with varying diameters and thicknesses (t), lengths of 25, 300 and 350 mm, but with constant slenderness ratios D/t and D/L were thus studied. Relevant comparisons were raised, showing that the slenderness ratios are very important parameters that globally govern the percentage increase in energy absorbed by tubular structures after cork-filling during an impact loading. http://www.sciencedirect.com/science/article/B6V49-4N0HJHH-3/1/20220e1e6296e934fc8342c290dbce43