Experiment Operation During Apollo IVA at 0-g

Experiment: Heat Flow and Convection

Acronym: HFC

PI/Engineer: Tommy C. Bannister/MSFC
Other Contacts: None

Apollo Flight Nos.: 14
Apollo Exp't No. None

Discipline: Fluid Dynamics (1700) Materials Science - Fluids (2610)

Weight: 3.2 kg
Dimensions: 23 x 23 x 9.6 cm

Manufacturer: Marshall SFC (with Lockheed Missiles and Space Co.?)

Description/Purpose:
Three different types of test cells -- radial, flow pattern, and zone -- were used to detect convection directly, or detect convective effects by measurement of heat flow rates in fluids. Each cell contained a small electric heater, powered by the spacecraft 28 VDC system. Seven tests were made, each requiring 10 to 15 min. The data was recorded by the 16 mm Data Acquisition Camera (DAC). The heat flow rates were visually displayed by color-sensitive, liquid crystal thermal strips and the color changes filmed with the DAC. It was demonstrated that surface tension can produce Benard cells in a liquid, independently of gravity-induced convection. Zone heating of liquid samples produced an unexpected cyclic heat-flow pattern. See fig. 5-3 in Mission Report for photo.

The radial cell was a circular cell filled with CO2 used to test radial heat flow. The cell, a cylindrical dish with a small heater in the center, was covered by a plastic film coated with a liquid crystal that indicated the temperature changes.

The flow pattern cell was designed to test the convective flow pattern induced in an oil layer by thermal changes in surface tension. It was a shallow aluminum dish which was uniformly heated from the bottom. Thin layers of Krytox® (containing aluminum flakes for visibility) were open to the spacecraft atmosphere and were thus unconfined.

The zone cells were composed of two transparent cylinders with heaters in the center. One contained water and the other a sugar solution. Liquid crystal strips located along the central axis of each cylinder and on the surface allowed the convection to be viewed on the basis of color maps, signifying heat flow.

Unloading from the LM: NA

Transporting by foot or MET: NA

Loading/unloading tools/exp'ts : NA

Site Selection:
In the lower equipment bay during operation.

Deploying experiment:
The box had two doors which opened. The DAC was attached via a short rod.

Check-out of experiment: No comments by crew.

Operation of experiment:
No operations document was found, but the experiment drawing shows an on/off switch, a cell selector/heater level select switch, and some knobs for the introduction and removal of the Krytox® oil. Seven experiments were performed, each requiring 10 to 15 minutes. The crew commented that the procedures and equipment were in good shape and that it was easy to accomplish the experiment.

Repairs to experiment:
When filling the cup with Krytox® fluid it did not flow evenly over the bottom. The crew used a finger to try to push the fluid to the bottom, over the heating element, and some of it did stay, but they never visually saw Benard cells as they expected.

Recovery/take-down of experiment: No comments by crew.

Stowing experiment for return: No comments by crew.

Loading/unloading samples : Krytox® was added to the flow pattern cell from a reservoir by turning a knob.

Loading of exp't/samples into the LM: NA

Stowing of package once in the LM: NA

Sampling operations - soil, rocks: NA

Trenching: NA

Raking: NA

Drilling: NA

Navigating/recognizing landmarks: NA

Were there any hazards in the experiment?
i.e. hazardous materials (explosive, radioactive, toxic), sharp objects, high voltages, massive, bulky, tripping hazards, temperatures?
No.

Was lighting a problem? No

Were the results visible to the crew? Yes

Would you recommend any design changes?
The experiment flew again on A-17.

Were any special tools required?
The 16 mm Data Acquisition Camera was used.

Was the orientation of the experiment (i.e. horizontal/vertical) important? Difficult?
No.

Was the experiment successful? Yes

Were there related experiments on other flights?
Apollo 17 Heat Flow & Convection Experiment See Skylab, Shuttle, Spacelab databases.

Where was it stored during flight?
CM aft bulkhead storage locker A8.

Were there any problems photographing the experiment?
No.

What pre-launch and cruise req'ts were there?
NA

What was different between training and actual Operation?
No comments by crew.

What problems were due to the suit rather than the experiment?
NA

Any experiences inside the CM of interest from the experiment/operations viewpoint?
Performed on trans-Earth coast with live color television during a press conference. It was also filmed.

References:

A-14 Mission Report

NASA TM X-64735, Heat Flow and Convection Demonstration (Apollo 14), 1973

Apollo Program Summary Report, section 3.6 Inflight Demonstrations, JCS-09423, April, 1975.

Apollo 14 Technical Crew Debriefing 17 February 1971, in the JSC History Office.

Apollo Stowage List - Apollo 14, MSC, 9 February 1971