Measurements of heat-transfer coefficients, friction factors, and velocity profiles for air flowing parallel to closely spaced rods

Conference · Tue Nov 28 04:00:00 EST 1961

OSTI ID:4866586

Palmer, Luther D.; Swanson, Leonard L.

The design of gas-cooled reactors with solid-rod fuel elements is predicated on knowledge of the-pressure-drop and heat-transfer characteristics within the reactor core. Heat-transfer and fiuid-dynamic studies were made with air fiowing parallel to the rods of a seven-rod cluster. The parallel rods were equally spaced in a triangalar array with a 1.015 ratio of center-to-center distance to rod diameter, the rod surfaces forming flow passages of tricuspidshaped cross section. Average and local heat-transfer film coefficients, pressure drops, and Velocity profiles were measured under established hydrodynamic conditions. The measured average heat-transfer film coefficients were approximately equal to those for smooth round ducts; however, the peripheral variation of the local coefficients at a Reynolds number of 20,000 was 0.5 to 1.3 of the average values, Fanning friction factors calculated from staticpressure-drop measurements made along the length of a flow passage were approximately 5% higher than those for smooth round ducts over a Reynolds number range of 3000 to 30,000. The velocity structure in the flowing gas was determined at a Reynolds number of 20,000. The peripheral variation of the ratio of local to bulk mean velocity was found to be very nearly equal to the ratio of the local to average heat-transfer coefficient. This agreement of the local and average heat-transfer data is to be expected from the analogy between fluid friction and heat transfer. (auth)

• Research Organization: General Dynamics Corp., San Diego, CA (United States). General Atomic Div.
• Sponsoring Organization: US Atomic Energy Commission (AEC)
• NSA Number: NSA-16-013246
• OSTI ID: 4866586
• Report Number(s): GA-1787
• Country of Publication: United States
• Language: English

Related Subjects

AIR
ANALOG SYSTEMS
CONFIGURATION
DIAGRAMS
ENGINEERING AND EQUIPMENT
FILMS
FLUID FLOW
FLUIDS
FRICTION
FUEL CANS
FUEL ELEMENTS
GAS COOLANT
GAS FLOW
HEAT TRANSFER
HYDRODYNAMICS
MATHEMATICS
MEASURED VALUES
PLANNING
PRESSURE
REACTOR CORE
REACTORS
RODS
SOLIDS
SURFACES
TURBULENCE
VELOCITY