Abstract
The influence of internal electrical leakage due to circulating currents flowing through velocity boundary layers and due to metallic elements in insulating walls (peg walls) is experimentally investigated. For this purpose a combustion-driven MHD generator is utilized. The active part of the generator test section is 60 cm in length with a constant cross-section of 3 x 12 cm{sup 2}. At typical operating conditions about 70 g/s of diesel light oil is burned with oxygen-enriched air, resulting in a thermal input of 3 MW, a fluid velocity of 500 to 700 m/s and a gas temperature of 2700 to 2900 Degree-Sign K at the channel inlet. KOH is used as the seed material. The magnetic field can be raised up to 1.95 Teslas. In the range of lower magnetic fields (B < 0.8T) it is shown that an observed open-circuit voltage agrees well with the theoretical value OBh which is defined in a one-dimensional MHD model. In other words, the circulating currents scarcely affect the open-circuit voltage. The theoretical basis for this fact is obtained by the use of a simple model. Experimental results obtained in several runs using three sets of insulating walls show that thermal boundary layers at
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Sasaki, Y.;
Ishibashi, E.;
[1]
Kasahara, T.;
Kazawa, Y.
[2]
- Hitachi Research Laboratory, Hitachi-shi, Ibaraki-ken (Japan)
- Hitachi Works, Hitachi Ltd., Hitachi-shi, Ibaraki-ken (Japan)
Citation Formats
Sasaki, Y., Ishibashi, E., Kasahara, T., and Kazawa, Y.
Internal Short-Circuiting Phenomena In An Open-Cycle MHD Generator.
IAEA: N. p.,
1968.
Web.
Sasaki, Y., Ishibashi, E., Kasahara, T., & Kazawa, Y.
Internal Short-Circuiting Phenomena In An Open-Cycle MHD Generator.
IAEA.
Sasaki, Y., Ishibashi, E., Kasahara, T., and Kazawa, Y.
1968.
"Internal Short-Circuiting Phenomena In An Open-Cycle MHD Generator."
IAEA.
@misc{etde_22200109,
title = {Internal Short-Circuiting Phenomena In An Open-Cycle MHD Generator}
author = {Sasaki, Y., Ishibashi, E., Kasahara, T., and Kazawa, Y.}
abstractNote = {The influence of internal electrical leakage due to circulating currents flowing through velocity boundary layers and due to metallic elements in insulating walls (peg walls) is experimentally investigated. For this purpose a combustion-driven MHD generator is utilized. The active part of the generator test section is 60 cm in length with a constant cross-section of 3 x 12 cm{sup 2}. At typical operating conditions about 70 g/s of diesel light oil is burned with oxygen-enriched air, resulting in a thermal input of 3 MW, a fluid velocity of 500 to 700 m/s and a gas temperature of 2700 to 2900 Degree-Sign K at the channel inlet. KOH is used as the seed material. The magnetic field can be raised up to 1.95 Teslas. In the range of lower magnetic fields (B < 0.8T) it is shown that an observed open-circuit voltage agrees well with the theoretical value OBh which is defined in a one-dimensional MHD model. In other words, the circulating currents scarcely affect the open-circuit voltage. The theoretical basis for this fact is obtained by the use of a simple model. Experimental results obtained in several runs using three sets of insulating walls show that thermal boundary layers at water-cooled metals are more conductive than expected and that the open- circuit voltage decreases because of leakage currents flowing through metal pegs, when the internal resistance of the generator is relatively large. Also, it is shown that an alumina coating is effective in reducing the leakage currents. (author)}
place = {IAEA}
year = {1968}
month = {Nov}
}
title = {Internal Short-Circuiting Phenomena In An Open-Cycle MHD Generator}
author = {Sasaki, Y., Ishibashi, E., Kasahara, T., and Kazawa, Y.}
abstractNote = {The influence of internal electrical leakage due to circulating currents flowing through velocity boundary layers and due to metallic elements in insulating walls (peg walls) is experimentally investigated. For this purpose a combustion-driven MHD generator is utilized. The active part of the generator test section is 60 cm in length with a constant cross-section of 3 x 12 cm{sup 2}. At typical operating conditions about 70 g/s of diesel light oil is burned with oxygen-enriched air, resulting in a thermal input of 3 MW, a fluid velocity of 500 to 700 m/s and a gas temperature of 2700 to 2900 Degree-Sign K at the channel inlet. KOH is used as the seed material. The magnetic field can be raised up to 1.95 Teslas. In the range of lower magnetic fields (B < 0.8T) it is shown that an observed open-circuit voltage agrees well with the theoretical value OBh which is defined in a one-dimensional MHD model. In other words, the circulating currents scarcely affect the open-circuit voltage. The theoretical basis for this fact is obtained by the use of a simple model. Experimental results obtained in several runs using three sets of insulating walls show that thermal boundary layers at water-cooled metals are more conductive than expected and that the open- circuit voltage decreases because of leakage currents flowing through metal pegs, when the internal resistance of the generator is relatively large. Also, it is shown that an alumina coating is effective in reducing the leakage currents. (author)}
place = {IAEA}
year = {1968}
month = {Nov}
}