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Title: Measurement of Turbulent Flow Phenomena for the Lower Plenum of a Prismatic Gas-Cooled Reactor

Mean velocity field and turbulence data are presented that measure turbulent flow phenomena in an approximately 1:7 scale model of a region of the lower plenum of a typical prismatic gas-cooled reactor (GCR) similar to a General Atomics design (Gas-Turbine-Modular Helium Reactor). The datawere obtained in the Matched-Index-of-Refraction (MIR) facility at Idaho National Laboratory (INL) and are offered as a benchmark for assessing computational fluid dynamics (CFD) software. This experiment has been selected as the first Standard Problem endorsed by the Generation IV International Forum. The primary objective of this paper is to document the experiment and present a sample of the data set that has been established for this standard problem. Present results concentrate on the region of the lower plenum near its far reflector wall (away from the outlet duct). The flowin the lower plenum consists of multiple jets injected into a confined crossflow—with obstructions. The model consists of a row of full circular posts along its centerline with half-posts on the two parallel walls to approximate flow scaled to that expected from the staggered parallel rows of posts in the reactor design. Posts, side walls and end walls are fabricated from clear, fused quartz to match themore » refractive index of the mineral oil working fluid so that optical techniques may be employed for the measurements. The benefit of the MIR technique is that it permits optical measurements to determine flow characteristics in complex passages and around objects to be obtained without locating intrusive transducers that will disturb the flow field and without distortion of the optical paths. An advantage of the INL system is its large size, leading to improved spatial and temporal resolution compared to similar facilities at smaller scales. A three-dimensional (3D) particle image velocimetry (PIV) system was used to collect the data. Inlet-jet Reynolds numbers (based on the hydraulic diameter of the jet and the timemean average flow rate) are approximately 4300 and 12,400. Uncertainty analysis and a discussion of the standard problem are included. The measurements reveal complicated flow patterns that include several large recirculation zones, reverse flow near the simulated reflector wall, recirculation zones in the upper portion of the plenum and complex flow patterns around the support posts. Data include three-dimensional PIV images of flow planes, data displays along the coordinate planes (slices) and presentations that describe the component flows at specific regions in the model.« less
Authors:
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Publication Date:
OSTI Identifier:
974430
Report Number(s):
INL/JOU-08-14823
Journal ID: ISSN 0029-5493; NEDEAU; TRN: US1002318
DOE Contract Number:
DE-AC07-05ID14517
Resource Type:
Journal Article
Resource Relation:
Journal Name: Nuclear Engineering and Design; Journal Volume: 240; Journal Issue: 2
Research Org:
Idaho National Laboratory (INL)
Sponsoring Org:
DOE - NE
Country of Publication:
United States
Language:
English
Subject:
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; BENCHMARKS; COMPUTERIZED SIMULATION; FLOW RATE; FLUID MECHANICS; GAS COOLED REACTORS; HELIUM; HYDRAULICS; QUARTZ; REFRACTIVE INDEX; RESOLUTION; REYNOLDS NUMBER; SCALE MODELS; TRANSDUCERS; TURBULENCE; TURBULENT FLOW; VELOCITY; WORKING FLUIDS; computational fluid dynamics; gas-cooled reactor; Standard Problem; turbulence; velocity field