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This paper investigates the effect of blowing ratio on the film cooling performance of a showerhead film cooled first stage turbine blade. The blade was instrumented with double-sided thin film heat flux gages to experimentally characterize the Nusselt number and film cooling effectiveness distributions over the surface of the blade. The blade was arranged in a two-dimensional, linear cascade within a transonic, blowdown type wind tunnel. The wind tunnel freestream conditions were varied over two exit Mach numbers, Me=0.78 and Me=1.01, with an inlet freestream turbulence intensity of 12% , with an integral length scale normalized by blade chord of 0.26 generated by a passive, mesh turbulence grid. The coolant conditions were varied by changing the ratio of coolant to freestream mass flux, blowing ratio, over three values, BR=0.60, 1.0, and 1.5 while keeping a density ratio of 1.7. Experimental results show that ingestion of freestream flow into the showerhead cooling plenum can occur below a blowing ratio of 0.6. Film cooling increases Nusselt number over the uncooled case and increasing the blowing ratio also increases Nusselt number. At a blowing ratio of 1.5 and Me=1.01 a large drop in effectiveness just downstream of injection on both the pressure and suction surfaces is evidence of jet liftoff. The blowing ratio of 1.0 was found to have superior heat load reduction over the blade surface at both freestream conditions tested. The blowing ratio of 1.0 reduced the heat load by as much as 39% and 32% at Me=0.78 and 1.01, respectively. / Master of Science

In this thesis, the turbine blade design eligible for ocean current conditions is proposed using blade element momentum theory. in the beginning, the performance of water turbines is evaluated by CFD (computational fluid dynamics) package code, so as to design the suitable turbine under various conditions. The blade design encompasses parameters of the hydrofoil selection and blade shape which affect the turbine performance. Shortly following the investigation of the aforementioned parameters, the turbine¡¦s performance with radius of two meter is also studied. The current conditions include the yaw and the pitch angle of the turbine relative to the current flow direction, as well as the periodic flow conditions on the performance of the water turbine. Lastly, the electricity generation is estimated by the present device. The results show that hydrofoils with less changes in the angle of attack with respect to the lift-drag ratio help enhance the turbine¡¦s performance. The feedback mechanism is added to the blade design procedure to make sure that the turbine design caters to the best angle of attack. A turbine with two-meter radius can garner 34% of the sea current energy at most, living up to the project goal of exceeding the efficiency of 30%. The simulated test indicates that the adequate enlargement of the blade not only sustains the maximal efficiency, but it also lowers the stress imposed on the blade. Given the ocean current conditions, it is also shown that the turbine¡¦s efficiency is proportional to the cubic cosine incident angle of inflow velocity alongside with the enlargement of the turbine radius. When it comes to the current electricity generation, from the in-situ measurement data, the current maximal velocity near the sea region is around 1.3 m/s. If incorporated with the self excited induction generator with the efficiency of 55%, a one-meter-radius turbine is estimated to be able to generate 530W at most, while a two-meter-radius turbine is estimated to generate 2.5KW. However, the use of the permanent magnet generator can produce 45% more electricity than a self excited induction generator.

As a sprint canoe athlete takes a stroke, the flow around their blade governs the transfer of power from the athlete to the water. Gaining a better understanding of this flow can lead to improved equipment design and athlete technique to increase the efficiency of their stroke. A method of modelling the complex motion of the sprint canoe stroke was developed that was able to simulate the transient 2-phase blade-water interactions during the stroke using computational fluid dynamics (CFD). The blade input motion was determined by extrapolating the changing blade position from video analysis of a national team athlete. To simulate the blade motion a rigid inner mesh translated and rotated according to the extrapolated blade path while an outer mesh deformed according to the translation of the inner mesh; allowing for independent motion of the blade throughout the xy-plane. Instabilities associated with the blade piercing a free surface were dealt with by using a piecewise solution. The developed model provided a first look into the complex hydrodynamics of the sprint canoe stroke. Examination of the resultant flow patterns showed the development and shedding of tip and side vortices and the resultant pressure on the blade. Late in the catch, there was an unrealistic drop in the net force on the blade which was attributed to the over-rotation of the blade causing the top two-thirds of the blade to accelerate the near surface water forward. The inclusion of an approximated shaft flexibility showed the ability to improve the net force to more realistic values. / Thesis / Master of Applied Science (MASc)

An experimental study on the application of Digital Image Correlation (DIC) to measure the deformation and strain of rotating blades is described. Commercial DIC software was used to obtain measurements on three different types of rotors with diameter ranging from 18 to 39 and with varying flexibility to explore applicability of the technique over a breadth of scales. The image acquisition was synchronized with the frequency of rotation such that images could be obtained at the same phase and the consistency of measurements was observed. Bending and twist distributions were extracted from the data with deformation as high as 0.4 measured with a theoretical accuracy of 0.0038 and span-wise resolution of 0.066. The technique was demonstrated to have many advantages including full-field high resolution results, non-intrusive measurement, and good accuracy over a range of scales. The span-wise deformation profiles from the DIC technique are used in conjunction with Blade Element Momentum Theory to calculate the thrust and power consumed by the rotor with rigid vi blades; results are comparable to load cell measurements albeit thrust is somewhat under-predicted and power is over-predicted. Overall, the correlation between DIC calculated thrust and BEMT approximations for comparable blades with constant pitch were within 12% through the onset of stall. Measurement of flexible blade deformation that would not have been possible with other techniques demonstrated the utility of the DIC method and helped to confirm predictions of flexible blade behavior. / text

The origins of Clovis technology and the nature and timing of the first populations to reach the Western Hemisphere is one of the most contentious issues in American archaeology. With the rejection of “Clovis-first”, many scholars consider that all colonising migrations followed a route out of Asia and across Beringia into North America. However, none of the technologies present in the far northeast of Asia or Beringia exhibit the manufacturing processes that were used in Clovis. To address this enigma, Stanford and Bradley proposed a radical alternative for the origins of Clovis. They argue that a small pioneering group of Solutreans crossed the Atlantic ice sheets of the LGM and reached the shores of North America. The basis for this argument stems from technological similarities between Clovis and the Solutrean, as well as from climatic, oceanographic, and ethnographic data. Biface manufacture is at the centre of their technological analysis, specifically comparing the reduction sequences of the distinctive Solutrean laurel leaf points and comparing them to Clovis points. This thesis tests the assumption of Stanford and Bradley that the blade manufacturing technologies of Clovis and Solutrean were “virtually identical”. By analysing the blade manufacturing processes from the Solutrean assemblage at Laugerie-Haute and the Clovis assemblage from the Gault site and comparing them to the broader technological patterns present across Eurasia between ~30,000 BP and 11,000 BP; this thesis supports the findings of Stanford and Bradley with the amendment that Clovis specifically intended to produce curved blades but did not use blades to produce projectile points. While convergence cannot be completely ruled out, there is a lack of evidence that would explain the number of similarities in the manufacturing processes. Thus it remains highly likely that interaction across the ice-edge corridor of the Atlantic may have occurred during the LGM.

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