Orbiter Flash Evaporator: Flight Experience and Improvements

O’Connor, Edward W.; Zampiceni, John J.; Cerna, Nanette F.; Fuller, Michael J.

doi:10.4271/972262

Cited by 10 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This hardware cools the Orbiter main coolant loop to 4 °C during certain mission phases. Although the FES has been mostly successful, some past shuttle missions have had failures of this hardware [1]. It is thought that unexpected icing caused the failure.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Experimental Studies of Spray Deposition on a Flat Surface in a Vacuum Environment

Golliher

Yao

2016

Proceeding of First Thermal and Fluids Engineering Summer Conference

View full text Add to dashboard Cite

Cooling of spacecraft components in the space environment is an on-going research effort. The electronics used in modern spacecraft are always changing and the heat flux is increasing. New, one-of-a-kind missions require new approaches to thermal control. In this research, under vacuum conditions, a pulsed water spray impinged on a small disc, while a high speed data acquisition system recorded the temperature histories of this copper disc. The water droplets froze quickly and accumulated on the disc as the spray continued. After the spray stopped, the frozen water that remained on the disc then sublimated into the vacuum environment and cooled the disc. This paper examines two important aspects of this process: 1) the difference in spray start up and shutdown in a vacuum environment versus in a standard atmospheric pressure environment, and 2) the water utilization efficiency in a vacuum environment due to the effects of drop trajectories and drop bouncing on the surface. Both phenomena play a role during spray cooling in a vacuum. This knowledge should help spacecraft designers plan for spray cooling as an option to cool spacecraft electronics, human metabolic generated heat, and heat from other sources.

show abstract

Section: Introductionmentioning

confidence: 99%

“…A steam outlet exhausted to the vacuum of space. Figure 1 shows a cut-away drawing of the FES with the Inlet and Outlet coolant loop interfaces and a depiction of the spray impinging on the wall [1]. Figure 2 shows the location of the FES relative to the other thermal control hardware.…”

Section: Introductionmentioning

confidence: 99%

Experimental Studies of Spray Deposition on a Flat Surface in a Vacuum Environment

Golliher

Yao

2016

Proceeding of First Thermal and Fluids Engineering Summer Conference

View full text Add to dashboard Cite

show abstract

“…The desired system pressure and temperature were always above the triple point of water, so that freezing would hopefully never occur. Although the FES has been mostly successful, some past shuttle missions have had anomalies of this hardware [1]. It is thought that unexpected icing caused the issue and that the anomalies of the FES were caused by some blockage or other inability of the passive backpressure device to create the proper system pressure within the FES.…”

Section: Introductionmentioning

confidence: 99%

Exploration of Impinging Water Spray Heat Transfer at System Pressures Near the Triple Point

Golliher

Yao

2013

Volume 8B: Heat Transfer and Thermal Engineering

View full text Add to dashboard Cite

The heat transfer of a water spray impinging upon a surface in a very low pressure environment is of interest to cooling of space vehicles during launch and re-entry, and to industrial processes where flash evaporation occurs. At very low pressure, the process occurs near the triple point of water, and there exists a transient multiphase transport problem of ice, water and water vapor. At the impingement location, there are three heat transfer mechanisms: evaporation, freezing and sublimation. A preliminary heat transfer model was developed to explore the interaction of these mechanisms at the surface and within the spray.

show abstract

“…While the Space Shuttle's FES used cyclic water spray cooling of enhanced surfaces (Triangular grooves) to cool freon based heat exchangers (Nason et al, 1985;O'Connor et al, 1997), work in the area of spray cooling with enhanced surfaces has been very limited. Most previous studies that have examined enhanced surfaces have done so primarily from the perspective of surface roughness.…”

Section: Spray Cooling Enhancementsmentioning

confidence: 99%

Investigation of Enhanced Surface Spray Cooling

Silk

Kim

Kiger

2004

Heat Transfer, Volume 2

View full text Add to dashboard Cite

Phase change technology is a science that is continually finding new applications, from passive refrigeration cycles to semiconductor cooling. The primary heat transfer techniques associated with phase change heat transfer are pool boiling, flow boiling, and spray cooling. Of these techniques, spray cooling is the least studied and the most recent to receive attention in the scientific community. Spray cooling is capable of removing large amounts of heat between the cooled surface and the liquid, with reported heat flux capabilities of up to 1000 W/cm 2 for water. Many previous studies have emphasized heat flux as a function of spray parameters and test conditions.Enhanced spray cooling investigations to date have been limited to surface roughness studies. These studies concluded that surface tolerance (i.e. variations in machined surface finish) had an impact upon heat flux when using pressure atomized sprays.Analogous pool boiling studies with enhanced surfaces have shown heat flux enhancement. A spray cooling study using enhanced surfaces beyond the surface roughness range may display heat flux enhancement as well.In the present study, a group of extended and embedded surfaces (straight fins, cubic pin fins, pyramids, dimples and porous tunnels) have been investigated to determine the effects of enhanced surface structure on heat flux. The surface enhancements were machined on the top surface of copper heater blocks with a crosssectional area of 2.0 cm 2 . Measurements were also obtained on a flat surface for baseline comparison purposes. Thermal performance data was obtained under saturated (pure fluid at 101 kPa), nominally degassed (chamber pressure of 41.4 kPa) and gassy conditions (chamber with N 2 gas at 101 kPa). The study shows that both extended and embedded structures (beyond the surface roughness range) promote heat flux enhancement for both degassed and gassy spray cooling conditions. The study also shows that straight fins provide the best utilization of surface area added for heat transfer. An Energy conservation based CHF correlation for flat surface spray cooling was also developed. CHF predictions were compared against published and non-published studies by several researchers. Results for the correlations performanceshow an average mean error of ±17.6% with an accuracy of ±30% for 88% of the data set compared against.

show abstract

Orbiter Flash Evaporator: Flight Experience and Improvements

Cited by 10 publications

References 0 publications

Experimental Studies of Spray Deposition on a Flat Surface in a Vacuum Environment

Experimental Studies of Spray Deposition on a Flat Surface in a Vacuum Environment

Exploration of Impinging Water Spray Heat Transfer at System Pressures Near the Triple Point

Investigation of Enhanced Surface Spray Cooling

Contact Info

Product

Resources

About