THE EFFECT OF INLET PRESSURE ON STEAM FLOW BEHAVIOR ACROSS A CONVERGENT-DIVERGENT NOZZLE

W. Mashi, Hussein; Kh. Al-Taie, Arkan; M. Al-Kafagy, Mohammed

	THE EFFECT OF INLET PRESSURE ON STEAM FLOW BEHAVIOR ACROSS A CONVERGENT-DIVERGENT NOZZLE
Al-Qadisiyah Journal for Engineering Sciences
Article 1, Volume 8, Issue 3, 2015, Pages 267-283 PDF (0 K)
Authors
Hussein W. Mashi; Arkan Kh. Al-Taie; Mohammed M. Al-Kafagy
Abstract
Convergent-Divergent nozzle has many applications especially in steam turbine. The aim of this work is to see the effect of varying inlet pressure on steam behavior through the C-D nozzle. This was done experimentally and numerically. In the experimental part, a C-D nozzle was designed and fabricated in a test section. Steam was fed from boiler at range of (0.69-0.36) bar at saturation temperature for each pressure. Shadowgraph optical method was used to see the formation of shock waves and condensation zone. In the numerical part, the nozzle was simulated using FLUENT under ANSYS code 15.0. In the experimental results, it was found that the most important influence of rapid condensation on the pressure distribution is occurred downstream the through area, when the flow in the divergent part is termed supersonic the heat release causes a pressure rise in the zone of rapid condensation. Shock wave appears in the divergent part due to over-expansion. Each of condensation zone and shock wave were showed by using shadowgraph optical method. In the numerical approach, droplet growth rate contour are presented. The maximum droplet growth rate is (1020 micron /sec) and occurred downstream the throat area. The comparison of experimental and numerical results show good agreement
Keywords
D nozzle; steam condensation; Shock wave; over; Expansion; shadowgraph

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