Pressure differences across topography generate a form drag that opposes the flow in the water column, and viscous and pressure forces acting on roughness elements of the topographic surface generate a frictional drag on the bottom. Form drag and bottom roughness lengths were estimated over the East Flower Garden Bank (EFGB) in the Gulf of Mexico by combining an array of bottom pressure measure...

An experimental study was performed to investigate the lift and drag coefficient of multiple wing. Most of the previous works carried out to increase the lift force and reduce the drag force having the more efficient and effective design. The aim of this project is to investigate the effect of multiple wings on lift and drag force. To perform this investigation a model of multiple wings is cons...

The present study demonstrates how the Genetic Algorithm (GA), coupled with the CFD solvers ARC2D for 2D and KTRAN for 3D problems, can successfully be applied to the airfoil and wing aerodynamic drag minimization. The geometry of airfoil and wing sections is represented by a B-spline curve. The actual values of the coordinates of the control nodes for the B-spline curve are designated as the d...

Experiments are carried out to study static pressure distribution and drag variations over NACA0018 aerofoil and over an automobile dome. Static pressure coefficients are calculated along the chord length for different angles of attack for both the test models and the results are compared. Further, the relationship between coefficient of drag and Reynolds number has been arrived for different a...

Meso-scale structure existing in the form of particle clusters or strands in concurrent-up gas–solid two-phase flow has been extensively corroborated in experimental research. However, its significant effects on interfacial drag coefficient are seldom taken into account in current computational fluid dynamic (CFD) simulations by using the two-fluid models. The energy-minimization multi-scale (E...

Nylon (PA) netting is widely used in purse seines and other fishing gears due to its high strength and good sinking performance. However, hydrodynamic properties of nylon netting of different characteristics are poorly understood. This study investigated hydrodynamic characteristics of nylon netting of different knot types and solidity ratios under different attack angles and flow velocities. I...

This paper investigates the relationships between friction velocity, 10m drag coefficient, and 10m wind speed using data collected at two offshore observation towers (one over the sea and the other on an island) from seven typhoon episodes in the South China Sea from 2008 to 2014. The two towers were placed in areas with different water depths along a shore-normal line. The depth of water at th...

The flow of a non-Newtonian, power-law fluid, directed normally to long, two-dimensional horizontal bodies, is considered in the present note. It is found that for low Reynolds numbers (Re ≤ 0.1) and a low power-law index (shear-thinning fluids) the drag coefficient always obeys the relationship cD = A/Re, whereas at a high power-law index (shear-thickening fluids) the drag coefficient tends to...

In this paper, we analyze the trajectory and body attitude data of Felix Baumgartner's supersonic free fall through the atmosphere on October 14, 2012. As one of us (UW) was scientific advisor to the Red Bull Stratos team, the analysis is based on true body data (body mass, wetted pressure suit surface area) and actual atmospheric data from weather balloon measurements. We also present a fully ...

We show how time-dependent magnetic fields lead to spin motive forces and spin drag in a spinor Bose gas. We propose to observe these effects in a toroidal trap and analyze this particular proposal in some detail. In the linear-response regime we define a transport coefficient that is analogous to the usual drag resistivity in electron bilayer systems. Because of Bose enhancement of atom-atom s...