日本財団 図書館

共通ヘッダを読みとばす


Top > 技術 > 海洋工学.船舶工学.兵器 > 成果物情報

Recent Advances in Marine Science and Technology, 2002

 事業名 海洋科学技術に関する太平洋会議の開催
 団体名 国際海洋科学技術協会 注目度注目度5


IMPROVEMENT OF WAVE POWER ECONOMY BY TERMINATOR BACKWARD BENT DUCT BUOY WITH CYLINDER DUCT
 
Y. Masuda1, A. Thakker2, T. Lewis3 and Xi. Liang4
 
1The Pacific Society
JAPAN
 
2Wave Energy Research Team, University of Limerick, IRELAND
 
3University of Cork, IRELAND
 
4Guangzhou Institute of Energy Conversion
Chinese Science Academy, CHINA
 
ABSTRACT
 
It is commonly established that wave power has a higher power density than wind power. The wave energy power generation device which makes use of air turbine was developed from navigational buoy and from test of Kaimei.
 
A new device "Backward Bent Duct Buoy" developed and was found that conversion efficiency was ten times greater that found from Kaimei. Also, the mooring force was significantly reduced. It was found from the water tank test, based on single float, that terminator BBDB can absorb wave power in wide width of wave front. Test on two and three floats terminator were conducted. Based on the results, wave power generator cost in open sea was estimated to be 10 Euro Cent in high power wave density wave sites, such as Ireland (60 KW/m) by 1:36 scale three floats terminator BBDB model. Also, it was estimated the cost to be 15 Cent Euro in low power wave density, such as Japan (10 KW/m) by 1:25 scale model.
 
CHARACTERISTIC OF WAVE POWER
 
Solar power (150 watts/square meter) is highly concentrated to wave power through wind blow on wide sea surface, and it is transmitted as swell from far distant area. Table 1 shows wind and wave conditions with fully developed sea state.
 
Table 1. Comparison of wind power and wave power by wind speed
(Wind speed U m/s) (Wave height Hs m) (Wave period Second) (Wave Power KW/m) (Wind Power KW/square meter)
5.1 0.55 3.3 5 0.08
10.3 2.3 6.6 16 0.67
15.4 5.0 9.9 120.2 2.3
20.6 9.0 13.2 520 5.4
25.7 14.0 16.5 1600 10.0
 
In the case of 15 m/s wind speed, wave power through 1 m width is equal to solar power of 500 square meters, and wind power of 50 square meters. Wind power is proportional to wind speed cubed. While fully developed wave power is to wind speed raised to the fifth Power. It is evident that wave power concentrates wind power in dramatic proportions. Therefore use of wave power will be a much better way than solar or wind usage.
 
Wave power density in the world is shown in Figure 1. High wave power such as 60 KW/m is reported in Ireland, low wave power such as 10 KW/m is reported in Japan and middle wave power such as 20 KW/m is reported in many islands including Hawaii. It is desired to generate electric power economically in not only high wave power areas (60 KW/m. Ireland), but also in low wave power area (10 KW/m such as Japan).
 
Figure 1. Wave power power distribution in the world
(produced by USA National Climate Center)
 
VARIOUS WAVEPOWER GENERATOR
 
There have been various wave power devices studied: the Oscillating Water Column (OWC) with floating buoy (Fig.2), Center pipe Buoy (Fig.3) Kaimei Buoy (80m long, 12m wide.)
 
Figure 2. Center pipe Buoy
 
Figure 3. Ship shape Kaimei Buoy
 
Figure 4. Original Single Float BBDB Model
 
Kaimei sea test was conducted at Yura Japan Sea from 1976 to 1984. Safety and long life of wave power device were confirmed, but conversion efficiency from wave power to air output was not good enough. In order to improve the efficiency, Backward Bent Duct Buoy (BBDB) was proposed. As shown in Figure 4, BBDB has an air chamber in the bow, and the duct is bent to backward, it opens to the stern. Air output per the same area of air chamber improved power ten times higher than Kaimei. The Buoy length was decreased to 30%, and mooring force was decreased significantly by function of oscillating water in the bent duct.
 
Mighty Whale (Fig.5) is another type that has Frontward Bent Duct. It was tested by JAMSTEC for the past four years on the Pacific side of Japan. This buoy is 50 m long and 30 m wide. The test by JAMSTEC will finish soon
 
At this time a 200 KW project named B2D2 (same as BBDB) started in Ireland by Dr Tony Lewis of Cork University. We wish to support this Ireland's test. After this single BBDB study, Terminator BBDB will be studied to use wider width of wave front.
 
Figure 5. Mighty Whale
 
CHARACTERISTIC OF OPEN SEA WAVE
 
Open sea waves are irregular waves. Let's call 1/3 of the average highest significant waves Hs. We observe that Hs and wavelengths L have characteristics constant Hs/L. Wave scatter diagram from the Japan Sea and North Atlantic is shown in Figures 6 and 7. Highest wave is distributed in line of Hs/L=1/20 by dotted line. Average power wave is distributed in line of Hs/L=1/40 by solid line. It is a very important wave characteristic that average power wave in Figures 6 and 7 are same. These are the basic wave characteristics in most of open seas.
 
Figure 6. Wave Scatter diagram of Japan Sea (Yura)
 
Figure 7. Wave Scatter diagram of North Atlantic
 
MODEL TEST
 
BBDB model tests were conducted in Japan, China, Ireland and India. Chinese model tests were two years ago.
 
Figure 8. The floating body model 3-3
 
Figure 9. Twin connection Floating body model
 
Figure 10. Trinity connection floating body model
 
Figure 11. Middle model 3-3
 
Figure 12. Small model 3-3
 
Table 2. Performance of Chinese model's optimal response point to peak periods only
Model plan Code Ho(m) Tpeak(S) Hi(m) ?P
mmAq
NWatts Q
cm
3/s
Hi/Ho ?P/H0 Eff(%) Effave(%)
Model 3-3 1-1 0.1 1.25 0.136 38.4 6.342 16.2 1.36 0.384 108.9  
Middle Model 3-3 M1-1 0.1 1.1 0.113 37.2 4.787 10.01 1.13 0.372 106  
Small Model 3-3 S1-1 0.1 0.96 0.1192 37.7 3,247 7,477 1.192 0.377 102
Twin Connection Model 3-3 2-1-1 0.1 1.25 0.1196 36.1 5.895 14.180 1.196 0.361 92.5 93.85
2-1-2 0.1186 41.1 6.066 14.065 1.185 0.411 95.2
Twin Connection Model 3-3 2-3-1 0.1 1.25 0.1234 37.6 6.515 14.695 1.234 0.376 101 103
2-3-2 7 0.1019 42.2 6.741 14.364 1.019 0.422 105
Twin Connection Model 3-3 2-4-1 0.1 1.25 0.1329 35.5 6.239 15.575 1.329 0.355 97.9  
2-4-2 0.1167 39.6 7.575 16.662 1.167 0.396 118.8
Three Connection Model 3-3 3-1-1 0.1 1.25
0.1134 38.9 6.151 13.708 1.134 0.389 95.9 89.4
3-1-2 7 0.0939 38.2 5.836 13.462 0.939 0.382 91
3-1-3   0.0981 32.9 5.213 13.571 0.981 0.329 81.3
Three Connection Model 3-3 3-3-1 0.1 1.24
0.1174 35.9 5.905 14.341 1.174 0.359 93.2 95.17
3-3-2 3 0.1028 36.8 6.564 17.165 1.028 0,368 103.6
3-3-3   0.1032 33.5 5.623 14.349 1.032 0.335 88.7
Three Connection Model 3-3 3-4-1 0.1 1.25 0.1296 39 6.998 15.289 1.296 0.39 109.8 104.5
3-4-2 0.1954 38.8 7.069 14.944 1.054 0.388 110.9
3-4-3 0.1093 31.8 5.915 15.333 1.093 0.318 92.8







サイトに関するご意見・ご質問・お問合せ   サイトマップ   個人情報保護

日本財団会長笹川陽平ブログはこちら

日本財団図書館は、日本財団が運営しています。

  • 日本財団 THE NIPPON FOUNDATION



ランキング
注目度とは?
成果物アクセスランキング
506位
(35,327成果物中)

成果物アクセス数
23,090

集計期間:成果物公開〜現在
更新日: 2022年11月26日

関連する他の成果物

1.PACON2002 Abstracts
2.PACON2002 Program
3.PACON2002 Forum
4.エンジンの定期メンテナンス記録
  [ 同じカテゴリの成果物 ]


アンケートにご協力
御願いします

この成果物は
お役に立ちましたか?


とても役に立った
まあまあ
普通
いまいち
全く役に立たなかった


この成果物をどのような
目的でご覧になりましたか?


レポート等の作成の
参考資料として
研究の一助として
関係者として参照した
興味があったので
間違って辿り着いただけ


ご意見・ご感想

ここで入力されたご質問・資料請求には、ご回答できません。






その他・お問い合わせ
ご質問は こちら から