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Dreaming
°íÀ¯ID
: darkrain2002
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: 12-10-06 05:29
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: 5169
±³Àç¿¡¼± ±æÀ̸¦ 1m ¸¦ °¡Á¤ÇÏ°í Ç®¾ú½À´Ï´Ù.
±×·±µ¥ ¾î¶² ½Ç¼ö¸¦ ÇÑ°ÇÁö.....Á¦°¡ Ǭ ¹æ¹ýÀÌ ¾îµð°¡ Ʋ·È´ÂÁö...Á¤¸» ¸ð¸£°Ú½À´Ï´Ù...¾Ë·ÁÁÖ¼¼¿ë..¤Ì¤Ì
½ºÅ×Æijë
Stefano
12-10-08 22:29
(1) ½Ç¸°´õ¿¡¼ÀÇ ¿Àü´Þ½Ä(Fourier's):
q = -kAdT/dr =-k(2¥ðrL)dT/dr .............(1) **ÁÖÀÇ: A=2¥ðrL ¿¡¼ rÀº º¯¼ö ±×·¯³ª krdT/dr = r°ú °ü°è¾ø´Â »ó¼ö
µû¶ó¼ ½Ç¸°´õÀÇ Heat Equation (1/r) d/dr[(krdT/dr)] =0 ==> dT = dr/r ==>ÀûºÐ T(r)=C1 ln r + C2
T(ri)=Ti, T(ro)=To ¶ó´Â ÀÓ°èÁ¶°ÇÀ» Àû¿ëÇؼ ÀûºÐ»ó¼ö C1,C2¸¦ ±¸Çϸé
T(r)=(Ti-To) ln(r/ro)/ln(ri/ro) + To ....(2) ÀÌ °ªÀ» (1)½ÄÀÇ ¿Àü´Þ½Ä¿¡ ´ëÀÔ
q =2¥ðL*k*(Ti-To)/ln(ro/ri) ....................(3)
À̽ÄÀ» Áú¹®¿¡¼ÀÇ q= Alm*k*(Ti-To)/¥Är = 2¥ð*(rlm)*k*(Ti-To)/¥Är ½Ä°ú ºñ±³ÇØ º¸¸é ¹«¾ùÀÌ Æ²·È´ÂÁö ¾Ë ¼ö ÀÖÀ» °ÍÀÔ´Ï´Ù.
(2) °á·ÐÀûÀ¸·Î ¿Àü´Þ ÀúÇ× R = ¥Är/(2¥ð*rlm*L*k)·Î ±¸ÇÏ¸é ¾ÈµÇ°í R= ln(ro/ri)/(2¥ð*L*k)·Î °è»êÇØ¾ß ÇÕ´Ï´Ù.
Áï ¹®Á¦Ç®ÀÌÀÇ ¿À¸¥ÂÊ Ã¹ÁÙÀÌ Æ²¸° ¼ö½ÄÀÔ´Ï´Ù.
Incropera, Dewitt, Bergmann, LavineÀÇ "Fundamentals of Heat and Mass Transfer" pp116-117¿¡ Àß ¼³¸íµÇ¾î ÀÖ½À´Ï´Ù. Âü°íÇϼ¼¿ä.
(1) ½Ç¸°´õ¿¡¼ÀÇ ¿Àü´Þ½Ä(Fourier's): q = -kAdT/dr =-k(2¥ðrL)dT/dr .............(1) **ÁÖÀÇ: A=2¥ðrL ¿¡¼ rÀº º¯¼ö ±×·¯³ª krdT/dr = r°ú °ü°è¾ø´Â »ó¼ö µû¶ó¼ ½Ç¸°´õÀÇ Heat Equation (1/r) d/dr[(krdT/dr)] =0 ==> dT = dr/r ==>ÀûºÐ T(r)=C1 ln r + C2 T(ri)=Ti, T(ro)=To ¶ó´Â ÀÓ°èÁ¶°ÇÀ» Àû¿ëÇؼ ÀûºÐ»ó¼ö C1,C2¸¦ ±¸Çϸé T(r)=(Ti-To) ln(r/ro)/ln(ri/ro) + To ....(2) ÀÌ °ªÀ» (1)½ÄÀÇ ¿Àü´Þ½Ä¿¡ ´ëÀÔ q =2¥ðL*k*(Ti-To)/ln(ro/ri) ....................(3) À̽ÄÀ» Áú¹®¿¡¼ÀÇ q= Alm*k*(Ti-To)/¥Är = 2¥ð*(rlm)*k*(Ti-To)/¥Är ½Ä°ú ºñ±³ÇØ º¸¸é ¹«¾ùÀÌ Æ²·È´ÂÁö ¾Ë ¼ö ÀÖÀ» °ÍÀÔ´Ï´Ù. (2) °á·ÐÀûÀ¸·Î ¿Àü´Þ ÀúÇ× R = ¥Är/(2¥ð*rlm*L*k)·Î ±¸ÇÏ¸é ¾ÈµÇ°í R= ln(ro/ri)/(2¥ð*L*k)·Î °è»êÇØ¾ß ÇÕ´Ï´Ù. Áï ¹®Á¦Ç®ÀÌÀÇ ¿À¸¥ÂÊ Ã¹ÁÙÀÌ Æ²¸° ¼ö½ÄÀÔ´Ï´Ù. Incropera, Dewitt, Bergmann, LavineÀÇ "Fundamentals of Heat and Mass Transfer" pp116-117¿¡ Àß ¼³¸íµÇ¾î ÀÖ½À´Ï´Ù. Âü°íÇϼ¼¿ä.
Dreaming
darkrain2002
12-10-09 15:25
°¨»çÇÕ´Ï´Ù.
ÀÏ´Ü ±¸ÇØÁֽŠR ·Î °è»êÀ» Çغ¸´Ï L ÀÌ Çѹø¿¡ ±¸ÇØÁö³×¿ë ¤¾
±×·±µ¥¿ä
À¯µµÇØÁֽŠ´ë·Î
q= 2¥ðL*k*(Ti-To)/ln(ro/ri) ¿©±â¿¡¼ ½ÃÀÛÀ» ÇؾßÇϴµ¥
q= Alm*k*(Ti-To)/¥Är ½ÃÀÛÇؼ Alm À» ±¸Ç߱⠶§¹®¿¡
Alm ÀÇ °ªÀÌ À߸ø ³ª¿Â°Ç°¡¿ä??
±×·¡¼ L °ªµµ À߸ø ³ª¿Â°Å°í¿ä??
q= Alm*k*(Ti-To)/¥Är = 2¥ðL*(rlm)*k*(Ti-To)/¥Är = 2¥ðL*k*(Ti-To)/ln(ro/ri)
Ç®¾î¼ ¾²¸é ±×³É ÀÌ·¸°Ô µÇ´Â°Å °°Àºµ.....ÀÌ°Ô ´Ù¸¥°ø½ÄÀΰ¡¿ä?¤Ì¤Ì
Á¦°¡..¼öÇÐÀûÀ¸·Î Àß ÀÌÇظ¦ ¸øÇϴ°Š°°Àºµ¥.....Á¦°¡ ´ä´äÇϳ׿ë..¤Ì¤Ì
°¨»çÇÕ´Ï´Ù. ÀÏ´Ü ±¸ÇØÁֽŠR ·Î °è»êÀ» Çغ¸´Ï L ÀÌ Çѹø¿¡ ±¸ÇØÁö³×¿ë ¤¾ ±×·±µ¥¿ä À¯µµÇØÁֽŠ´ë·Î q= 2¥ðL*k*(Ti-To)/ln(ro/ri) ¿©±â¿¡¼ ½ÃÀÛÀ» ÇؾßÇϴµ¥ q= Alm*k*(Ti-To)/¥Är ½ÃÀÛÇؼ Alm À» ±¸Ç߱⠶§¹®¿¡ Alm ÀÇ °ªÀÌ À߸ø ³ª¿Â°Ç°¡¿ä?? ±×·¡¼ L °ªµµ À߸ø ³ª¿Â°Å°í¿ä?? q= Alm*k*(Ti-To)/¥Är = 2¥ðL*(rlm)*k*(Ti-To)/¥Är = 2¥ðL*k*(Ti-To)/ln(ro/ri) Ç®¾î¼ ¾²¸é ±×³É ÀÌ·¸°Ô µÇ´Â°Å °°Àºµ.....ÀÌ°Ô ´Ù¸¥°ø½ÄÀΰ¡¿ä?¤Ì¤Ì Á¦°¡..¼öÇÐÀûÀ¸·Î Àß ÀÌÇظ¦ ¸øÇϴ°Š°°Àºµ¥.....Á¦°¡ ´ä´äÇϳ׿ë..¤Ì¤Ì
½ºÅ×Æijë
Stefano
12-10-12 20:22
Ʋ¸° °ÍÀÌ ¾Æ´Ï¶ó °°Àº ¼ö½ÄÀÎ °Í °°Àºµ¥¿ä.
Ʋ¸° °ÍÀÌ ¾Æ´Ï¶ó °°Àº ¼ö½ÄÀÎ °Í °°Àºµ¥¿ä.
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