DEVELOPMENT OF A DETAILED MEASUREMENT TECHNIQUE FOR TURBULENT FLOW CHARACTERIZATION IN FUEL BUNDLES

NALÍN, OSCAR; MARCEL CHRISTIAN PABLO; LAZO, PABLO; MASSON, V.

Xi?an, Shaanxi

Conferencia; International Topical Meeting on Nuclear Reactor Thermalhydraulics; 2017

American Nuclear Society (ANS), Xi'an Jiao Tong University

Investigating the flow behavior in fuel rod bundleshas been an active research topic since many decades. Nowadays, despite thegreat advances in computational fluid dynamic techniques and resources, blindbenchmarks have shown numerical results are still very dependent on schemes andclosure models. Moreover, most experimental studies in flow mixing and flowstructure identification were performed in simplified geometries and/or in avery limited test domain. In addition, reliable experimental data from mixing experiments inthe vicinity of a spacer grid in rod bundles are almost non-existent,especially with high spatial and temporal resolution.Generating experimental data relevant for fuelbundle geometries is costly and generally limited to a small measurementregion. In this work a novel non-intrusive technique is developed and tested inorder to characterize the flow in a geometry resembling a fuel bundle by usingof detailedpressure measurements. The measurement device makesuse of electronic micromachined deformable membrane differential pressure sensorswith fast dynamical response, allowing capturing local pressure fluctuations.Such differential pressure sensors are connected to a fix pressure tap and amovable pressure tap drilled in each of the rods. Each instrumented rod is freeto move both axially and azimuthally allowing scanning the static pressure dropvalues at the surface of the rod. In addition, by analyzing the static pressurefluctuations it is possible to capture valuable information of turbulencephenomenon such as the turbulence kinetic intensity and the turbulence powerspectrum in a wide spatial range, including regions within spacer grids.