Effect of orifice geometry and orifice to test section spacing on distribution of wall static pressure on a convex surface

Abstract

The experimental investigation is carried out to study the distribution of wall static pressure (Cp & Cpo) on the convex smooth surface by air jet impingement. A great deal of attention was paid to analyze the effects of orifice geometry for various flow and geometric conditions, a comparison of the wall static pressure coefficient is done for different orifice. The experimental results show that the wall static pressure on a convex test section is higher for rectangular orifice compared to other orifice. The wall static pressure decreases circumferentially from its maximum value at the stagnation point (θ = 0°) and also for higher Z/dh. Higher value of Cp and Cpo are obtained for unconfined flow. The experiments were performed with the following parameters: the jet Reynolds number (Re) = 10000–50000, the orifice-to- convex surface distance (Z/dh) = 1–5, Circumferential angle (θ) = 0° to 30°, Curvature ratio (D/dh), Orifice = Circular, Square, Triangle, Rectangle.

Study of Wall Static Pressure Distribution on Flat Surface by Impinging Submerged Jet from Non-circular Orifice

“…The graph of CP vs θ shows the independent characteristic of jet Re on the distribution of non-dimensional CP and CPO value for all Z/dj = 1 to 5 in both confined and unconfined flow condition, as all the curves take same profile for all jet Re (50000-10000) with some minor deflection in CP magnitude. Similar independency of jet Reynolds nd CPo was observed and highlighted in most studies [23][24][25]. It is also observed that the CP and CPo are dependent on flow restriction and non-dimensional jet exit distance (Z/dj) and lateral distance (X/dj) which are discussed in other sections.…”

“…This result indicates that high pumping power is required in the confined flow. Similar contributions are observed for circular, square, rectangular and triangular orifice in early studies [23]. journal.ump.edu.my/ijame ◄…”

“…In 2019 an experimental study carried by Singh and Prasad [22] shows 8-24% better result in the thermal performance factor for 45⁰ chamfered exit and also the outlined correlations for average Nusselt number. Hanchinal and Katti [23] used four different orifice geometries to analyse the distribution of CP and CPo on test surface. The study shows better results for circular jet when compared to square, rectangular and triangular jet.…”

Turbulent kinetic energy and self-sustaining tones: Experimental study of a rectangular impinging jet using high Speed 3D tomographic Particle Image Velocimetry

“…Like the parameters of the flow, the geometry of the jet orifice or the nozzle plays a critical role in the production of self-sustaining tones [10][11][12][13][14][15][16][17]. Sondhauss et al [18] showed that the Strouhal number relative to the frequency transmitted depends both on the distance between the jet outlet and the slotted plate, and on the speed of the jet, while remaining within the upper and lower limits of the velocity range that corresponds to the appearance of self-sustaining sounds.…”