Effect of Vertical Canard Location on Skin Friction Drag

This study investigates the viscous skin friction drag generation due to the three different vertical canard locations on the mid winger un-swept aircraft scaled-down model by using boundary layer measurements in the wind tunnel. The N22 airfoil was selected for the canard and the modified S1223 airfoil was selected for the wing. The laser cutting technique was employed for the fabrication of the wing, and canard airfoils, which gave sufficient dimensional accuracy to the model. The canard, wing, and fuselage were fabricated by balsa wood and strengthened by Aluminum stripes. The assembled model is tested in an open subsonic wind tunnel a fixed chord Reynolds number 3.8*106. The boundary layers were measured at 70% of the chord and at three different wingspan locations i.e. 30%, 60%, and 90% with 00 incidence angle. The canards were positioned at three vertical positions one at fuselage reference line (FRL) and the remaining two locations at ± 0.16 c from the FRL. The results were compared with wing-body alone and with three canard locations and found that the high canard configuration outperformed the other two configurations and also wing-body alone configuration as it provides half of the total drag. However, the high canard produces 15% more drag than the wing-body alone at the wing tip (90%).The aerodynamic performance of the high canard configuration was found to be significantly promising for the future use in drones and other small aircrafts.

Design of a Dislocation Well Pattern and Drilling of Shallow 3D Cluster Horizontal Wells for Development of Ultra Heavy Oil

The Junin block in Venezuela was known as an ultra heavy oil belt reserved in extra shallow layers (950ft-1,380ft) with unconsolidated formations. A cluster wells platform drilling was required for the Field Development Program (FDP). Optimisation of the well pattern and drilling of shallow 3D cluster horizontal wells for development of ultra heavy oil are presented in this paper. A well pattern of hand-shape dislocation was forwarded to enhance effective recovery of heavy oil in diamond blind area. Optimisation of the casing programs and control of the well trajectories as well as other key performance drilling were designed. A strict anti-collision barrier design and operation steps were worked out to assure the drilling safety. The loss-resistance, anti-collapse, stick-stuck proof, lubrication and reservoir protection were put into considerations for the drilling fluid design. Recovery of heavy oil was enhanced by means of electrical heating system. Drilling challenges such as shallow target zones, big build-up rate, long horizontal sections, great friction drag and torques, and well trajectories control were experienced and settled. Especially the puzzles of well trajectories control in unconsolidated formations, great friction drag and torques of strings in large displacement long horizontal sections for subsequent operations, and the unstable wellbore were tackled. A typical well data revealed that the horizontal displacement vs. TVD ratio was as high as up to 4.5. The setting depth of surface casing and the determination of KOP were critical to the horizontal wells with large displacement in shallow layers. Pressurized combined drilling and casing-running by means of top drive overcame the drag and torque and achieved planned TD and casing setting depth. The use of electrical wireline heating rod increased the temperatures in and close to the wellbore, and compensated the radius heat loss and avoided viscosity increase of heavy oil so that the output was maintained and improved. It was the first time for successful drilling of shallow 3D cluster horizontal wells with ratio of horizontal displacement vs. TVD over 3.5 in heavy oil belt of Venezuela. The innovative palm-shape dislocation of the well pattern design satisfied the demand of reservoir development and contributed to good production gain of heavy oil.

Decomposition of the mean friction drag on an NACA4412 airfoil under uniform blowing/suction

The application of drag-control strategies on canonical wall-bounded turbulence, such as periodic channel and zero- or adverse-pressure-gradient boundary layers, raises the question on how to distinguish consistently the origin of control effects under different reference conditions. We employ the RD identity (Renard & Deck, J. Fluid Mech., vol. 790, 2016, pp. 339–367) to decompose the mean friction drag and investigate the control effects of uniform blowing and suction applied to an NACA4412 airfoil at chord Reynolds numbers $Re_c=200\,000$ and $400\,000$ . The connection of the drag reduction/increase by using blowing/suction with the turbulence statistics (including viscous dissipation, turbulence kinetic energy production and spatial growth of the flow) across the boundary layer, subjected to adverse or favourable pressure gradients, is examined. We found that the inner and outer peaks of the contributions associated with the friction-drag generation show good scaling with either inner or outer units, respectively. They are also independent of the Reynolds number, control scheme and intensity of the blowing/suction. The small- and large-scale structures are separated with an adaptive scale-decomposition method, namely the empirical mode decomposition (EMD), which aims to analyse the scale-specific contribution of turbulent motions to friction-drag generation. Results unveil that blowing on the suction side of the airfoil is able to enhance the contribution of large-scale motions and to suppress that of small scales; however, suction behaves contrarily. The contributions related to cross-scale interactions remain almost unchanged with different control strategies.

Unsteady Convective MHD Flow and Heat Transfer of a Viscous Nanofluid across a Porous Stretching/Shrinking Surface: Existence of Multiple Solutions

The suspension of tiny solid particles inside the energy transport liquids could enhance their thermal conductivity as well as provide an efficient and inventive approach to significantly improve their properties of heat transport. Therefore, our aim is to explore the radiative two-dimensional unsteady flow of a viscous nanofluid about an aligned magnetic field that includes the joint effect of suction, velocity slip, and heat source across a porous convective stretching/shrinking surface. Initially, using non-dimensional variables, the nonlinear governing partial differential equations (PDEs) were transformed into ordinary differential equations (ODEs) which were subsequently solved with the help of bvp4c built-in package in MATLAB. The results declare that escalating the values of the unsteadiness parameter escalates the friction drag whereas it reduces with the escalation of the slip parameter. Furthermore, the heat transfer rate escalates with the escalation of radiation and concentration parameter, and the escalation of the heat source parameter causes to reduce the heat transfer rate. Finally, it is found that the rate of heat transfer and friction drag continuously improve and decline against the rising rates of stretching, respectively.

A study of a computational BVP for heat transfer and friction drag in magnetohydrodynamics viscous flow of a nanofluid subject to the curved surface

The ongoing work investigates the features of Joule heating and convective condition over a magnetohydrodynamic stagnation point flow of [Formula: see text] nanofluid moving across a curved surface. Moreover, mass suction is supposed through the stretching/shrinking surface. The initially developed model of partial differential equations is transformed into the ordinary ones assisted by suitable similarity variables. Subsequently, the ultimate nonlinear model of ordinary differential equations is solved with the help of a built-in function bvp4c package in MATLAB. Several graphical results are plotted to see the influence of various dimensionless parameters over the velocity, temperature, heat transfer, and friction drag. We found that there exists an escalation in temperature with increasing values of curvature, Eckert number, Hartmann number, and Biot number; however, the velocity profile declines with large curvature, ratio parameter, and high concentration of nanoparticles. It is also important to note that the friction drag rises with the mass suction, and reduces with vast curvature, whereas the rate of heat transfer improves with suction and Biot number but lowers with Eckert number and Hartmann number.