The dynamics of major flow structures were studied in a gas turbine model combustor for perfectly premixed swirlstabilized flames under a variety of reacting and non-reacting conditions using high-repetition-rate laser diagnostics. The studied combustor is a target case for the International Workshop on Advanced Measurement Techniques and Computational Methods for Premixed and Partially Premixe...

An experimental investigation of the parameters controlling the whistling frequency and amplitude of an orifice in a confined turbulent flow is undertaken. A circular single hole orifice with sharp edges, a hole diameter equal to 0.015 m and a thickness equal to 0.005 m, is arranged in an air test rig with an inner diameter equal to 0.03 m. The Mach number ranges around 0.02 and the Reynolds nu...

An experimental study is conducted on flow past a circular cylinder fitted with some tripping wires on its surface. The work investigates the dependency of the critical wire locations on the wire size and Reynolds numbers, and examines the wake and vortex shedding characteristics in an effort to advance the understanding of the critical wire effects beyond the existing literature. The primary a...

A = area of the rough wall Aj = jth equal subarea of the rough region, A=NA B = empirical constant for the mean velocity profile on a rough wall; Eq. (29) CA = A-weighting factor CF = overall skin friction coefficient, 1 L R L 0 cf dx1 c = speed of sound in free field cf = local skin friction coefficient, w= 1 2 0U 2 cf0 = local skin friction coefficient at a distance xle from the leading edge ...

Abstract The aim of this study is to investigate the fluid flow structure and heat transfer from an isothermal cylinder with a curved corner radius ratio ( r/R ) 0.5, attack angle α varied between 0° ≤ 45°. subjected airflow at Reynolds number Re = 180 Prandtl Pr 0.7. This focuses on effect forces, Strouhal number, Nusselt structure, wake bubble size. sensitivity time-mean drag lift forces inve...

Most wings and fins found in nature tend to be of low or moderate aspect-ratio. However, most experimental and numerical studies in this area of bio-hydrodynamics have focused on examining large or infinite aspect-ratio flapping foils. In the current study, an efficient, finite-difference based immersed boundary solver for computing flows with moving immersed boundaries has been developed to ex...

cdynp,i; cfric,i constants used to estimate the external torque per unit length on the body due to dynamic pressure and skin friction CoM centre of mass of the body; the centre of mass of a body segment is indicated as the segmental CoM. dpf days post fertilization Ekin,body total kinetic energy of the body ML2T−2 Ekin,int ‘internal’ kinetic energy of the body ML2T−2 Etr,CoM kinetic energy due ...

The relationship between tail (or wing) beat frequency (f(tail)), amplitude (A) and forward velocity (U) in animals using oscillatory propulsion, when moving at a constant cruising speed, converges upon an optimum range of the Strouhal number (St = f(tail) · A/U). Previous work, based on observational data and supported by theory, shows St falling within the broad optimum range (0.2<St<0.4) and...

The path to turbulence in the wake of cylinders with square crosssection is investigated by means of direct numerical simulation, employing a two-dimensional spectral element method and Floquet linear stability analysis. The critical Reynolds number for the onset of the three-dimensional instability modes A, B, C and QP are reported for cylinder incidence angles between 0° and 45°. The Strouhal...