Samir Armando Salamah

Modeling of Turbulent Heat Transfer from an Array of Submerged Jets Impinging on a Solid Surface

ABSTRACT Heat transfer from a row of turbulent jets impinging on a stationary surface is investigated numerically with the finite-difference algorithm SIMPLE. The jet-to-jet interaction, the geometric parameters of the jet array, and the effect of Reynolds number are investigated. The jets under consideration are submerged, planar, and exit the nozzle with a developed velocity profile. This study focuses on the turbulent regime (Re j up to 72,300) using the Lam-Bremhorst version of the low-Re k–ϵ model. The notorious overpredictions in the stagnation region are alleviated using the Yap correction. Transition from laminar to turbulent flow is predicted via the Schmidt-Patankar production-term-modification model. Good comparison with experimental data is shown. Model results show that heat transfer is a maximum at the stagnation point and decreases with distance along the plate. At some point, heat transfer may exhibit an increase due to transition to turbulence. There is also a local maximum in Nusselt number at the midpoint between two jets, where the jets collide. The uniformity of heat transfer on the plate is a function of where and whether transition to turbulence occurs and the magnitudes of heat transfer at the stagnation and collision points. The modeling approach used here effectively captures both the stagnation region behavior and the transition to turbulence, thus forming the basis of a reliable turbulence model.

HUTEC a high efficiency thermally regenerative fuel cell for space applications

The Hydrogen Thermo‐Electrochemical Converter (HYTEC) is an improved means of thermal‐to‐electrical energy conversion for space or other remote locations. The system is based on a fuel cell where the fuel element, hydrogen gas, is regenerated from the fuel cell product, metal hydrides. The HYTEC work at General Electric has resulted in a system concept design and supporting experimental data. Unique features in the system include the use of a niobium‐titanium alloy for the electrodes and a lithium‐sodium mixture to transport the hydride reaction product. Experimental data to date has shown the feasibility of the concept.

SP‐100 scaleup to 40 MWe

Human space exploration and utilization will require megawatts of electric power for propulsion and surface applications. SP‐100 nuclear technology being developed under the DOE/NASA/DOD Ground Engineering System contact is directly applicable to these missions. Designs of three scaleup systems delivering 5, 10 and 40 MWe using SP‐100 reactor technology in conjunction with both static and dynamic power conversion technologies provide attractive mass characteristics.

Experimental verification of the SP‐100 TEM pump analytical models

Validation of the TEM pump analytical model is conducted via experimental verification of the model prediction. Two key tests that have provided essential information toward this objective are the Magnetic Bench Test (MBT) and the ElectroMagnetic Integration Test (EMIT). The tests are briefly described and experimental results are compared with predictions of simulation models that form part of overall TEM pump performance model.

Effects of Rotating Stall on an Axial Fan Design

This paper presents the physical measurements and analysis of data pertaining to rotating stall observed during testing at the GE fan test facility located at Rensselaer Polytechnic Institute. Although never detected in actual GE applications, the rotating stall was encountered while testing fan cooling blade prototypes used in electrical generators. The effects of this phenomenon on the flow rate and pressure rise across the fan are considered, along with the frequency content of the adjacent flows on either side of the fan. Further, the effects of the addition of flow constrictions before and after the fan on the behavior of the rotating stall are investigated.Copyright

Generator Fan Test Facility to Quantify Axial Flow Fan Aerodynamic Performance

The General Electric fan test facility has been re-installed and commissioned in the Laboratory for Noise and Vibration Control Research, located on the second floor of the Jonsson Engineering Center (JEC 2110) in the Department of Mechanical, Aerospace and Nuclear Engineering at Rensselaer Polytechnic Institute, Troy NY. RPI provides a unique venue to have a fully dedicated facility with access to experts and graduate students specializing in different fields. A congruence of new interested RPI investigators, generator aerodynamic experts, the return of old collaborators, and the need to reduce cost and losses in generator components, conspired to re-commission an improved version of the original setup. The results presented show good correlation between CFD and measured performance.© 2010 ASME