查看“︁热扩散率”︁的源代码

在[[传热]]分析中，'''热扩散率'''（符号：<math>\alpha\,</math>，但注意<math>\kappa</math>、<math>D</math>和<math>k</math>都很常用）是[[热导率]]与[[容积热容]]之比。

:<math>\alpha = {k \over {\rho c_p}}</math>

其中：
* <math>k\,</math>：[[热导率]]（[[计量单位|单位]]：W/(m K)）
* <math>\rho c_p\,</math>：[[容积热容]]（单位：J/(m<sup>3</sup>K)）
* <math>\rho\,</math>：[[密度]]（单位：kg/(m<sup>3</sup>)）
* <math>c_p\,</math>：[[比热容]]（单位：J/(kg K)）

热扩散率的单位是m<sup>2</sup>/s。

对于普通的岩石来说，<math>\alpha\,</math> ~ 10<sup>-6</sup> m<sup>2</sup>/s。在300K，空气的热扩散率是0.000024 m<sup>2</sup>/s。

对于空气的热扩散率与绝对温度之间的关系，参见[https://web.archive.org/web/20080821201452/http://users.wpi.edu/~ierardi/PDF/air_alpha_plot.PDF]。

== 部分材料與物質的熱擴散率 ==
{| class="wikitable sortable"
|+部分材料與物質的熱擴散率<ref>{{cite book| title=Introduction to Heat Transfer|edition= 3rd|publisher=McGraw-Hill| year=1958| last1=Brown |last2= Marco}}  and {{cite book| last1=Eckert |last2=Drake| title=Heat and Mass Transfer| publisher=McGraw-Hill| year=1959| isbn=978-0-89116-553-8}} cited in {{cite book| first=J.P. |last=Holman| title=Heat Transfer| url=https://archive.org/details/isbn_9780070588745 | edition=9th| publisher=McGraw-Hill|year= 2002| isbn=978-0-07-029639-8}}</ref>
|-
! 材質 !!熱擴散率 (mm<sup>2</sup>/s)!!來源
|-
| [[Pyrolytic carbon|Pyrolytic graphite]], parallel to layers ||1220|| 
|-
|碳/碳纖維 at 25&nbsp;°C
|216.5
|<ref name="Casalegno2010" />
|-
|氦氣 (300 K, 1 atm)
|190
|<ref name="baierlein">{{cite book|title=CDC Handbook of Chemistry and Physics|publisher=Chemical Rubber Publishing Company|year=1992|editor-last=Lide|editor-first=David R.|edition=71st|location=Boston}} cited in {{cite book|last=Baierlein|first=Ralph|url=https://archive.org/details/thermalphysics00ralp|title=Thermal Physics|publisher=Cambridge University Press|year=1999|isbn=978-0-521-59082-2|location=Cambridge, UK|page=[https://archive.org/details/thermalphysics00ralp/page/372 372]|access-date=1 December 2011|url-access=registration}}</ref>
|-
| 純銀 (99.9%) ||165.63||
|-
|氫氣 (300 K, 1 atm)
|160
|<ref name="baierlein" />
|-
| [[金]]  ||127||<ref name="eleccool">{{cite journal |url=http://www.electronics-cooling.com/2007/08/thermal-diffusivity/ |title=Materials Data |author=Jim Wilson |date=August 2007 |access-date=2021-11-07 |archive-date=2021-11-08 |archive-url=https://web.archive.org/web/20211108224630/http://www.electronics-cooling.com/2007/08/thermal-diffusivity/ |dead-url=no }}</ref>
|-
| [[銅]] at 25&nbsp;°C  || 111||<ref  name="Casalegno2010">{{cite journal|title= Measurement of thermal properties of a ceramic/metal joint by laser flash method |journal= Journal of Nuclear Materials |volume=407 |issue=2|page=83 |author1=V. Casalegno |author2=P. Vavassori |author3=M. Valle |author4=M. Ferraris |author5=M. Salvo |author6=G. Pintsuk | year= 2010 |doi=10.1016/j.jnucmat.2010.09.032|bibcode = 2010JNuM..407...83C }}</ref>
|-
| [[鋁]] || 97|| <ref name="eleccool"/> 
|-
|矽
|88
|<ref name="eleccool" />
|-
| 鋁-10矽-錳-鎂 (Silafont 36) at 20&nbsp;°C   || 74.2|| <ref>{{cite journal |author1=P. Hofer |author2=E. Kaschnitz |title=Thermal diffusivity of the aluminium alloy Al-10Si-Mn-Mg (Silafont 36) in the solid and liquid states |journal=High Temperatures – High Pressures |volume=40 |issue=3–4 |page=311 |year=2011 |url=http://www.oldcitypublishing.com/HTHP/HTHPcontents/HTHP40.3-4contents.html |access-date=2021-11-07 |archive-date=2016-03-04 |archive-url=https://web.archive.org/web/20160304113208/http://www.oldcitypublishing.com/HTHP/HTHPcontents/HTHP40.3-4contents.html |dead-url=no }}</ref>
|-
| 6061-T6 鋁合金  || 64||<ref name="eleccool"/>
|-
|[[鉬]] (99.95%) at 25&nbsp;°C || 54.3||<ref>{{cite conference|conference=17th [[PLANSEE|Plansee]] Seminar |title= Measurement of the Thermophysical Properties of Pure Molybdenum |author1=A. Lindemann |author2=J. Blumm | year= 2009 |volume=3 }}</ref>
|-
| 鋁-5鎂-2矽-錳 (Magsimal-59) at 20&nbsp;°C  || 44.0|| <ref>{{cite journal |author1=E. Kaschnitz |author2=M. Küblböck |title=Thermal diffusivity of the aluminium alloy Al-5Mg-2Si-Mn (Magsimal-59) in the solid and liquid states |journal=High Temperatures – High Pressures |volume=37 |issue=3 |page=221 |year=2008 |url=http://www.oldcitypublishing.com/HTHP/HTHPcontents/HTHP37.3contents.html |access-date=2021-11-07 |archive-date=2016-03-04 |archive-url=https://web.archive.org/web/20160304131424/http://www.oldcitypublishing.com/HTHP/HTHPcontents/HTHP37.3contents.html |dead-url=no }}</ref> 
|-
|錫
|40
|<ref name="eleccool" />
|-
|水蒸氣 (1 atm, 400 K)
|23.38
|
|-
| 鐵 || 23||<ref name="eleccool" />
|-
|氬氣 (300 K, 1 atm)
|22
|<ref name="baierlein" />
|-
|氮氣 (300 K, 1 atm)
|22
|<ref name="baierlein" />
|-
|空氣 (300 K)
|19
|<ref name="eleccool" />
|-
| [[钢]], AISI 1010 (0.1% carbon)  || 18.8|| <ref>{{cite book|last=Lienhard|first=John H. Lienhard, John H. |title=A Heat Transfer Textbook|year=2019|publisher=Dover Pub|page= 715|edition=5th}}</ref>
|-
|氧化鋁 (polycrystalline)
|12.0
|
|-
| [[钢]], 1% carbon ||11.72|| 
|-
|Si<sub>3</sub>N<sub>4</sub> with [[carbon nanotube|CNTs]] 26&nbsp;°C
|9.142
|<ref name="Koszor2009">{{cite journal|author1=O. Koszor|author2=A. Lindemann|author3=F. Davin|author4=C. Balázsi|year=2009|title=Observation of thermophysical and tribological properties of CNT reinforced Si<sub>3</sub> N<sub>4</sub>|journal=Key Engineering Materials|volume=409|page=354|doi=10.4028/www.scientific.net/KEM.409.354|s2cid=136957396}}</ref>
|-
|Si<sub>3</sub>N<sub>4</sub> without [[carbon nanotube|CNTs]] 26&nbsp;°C
|8.605
|<ref name="Koszor2009" />
|-
| 304不鏽鋼 at 27&nbsp;°C   || 4.2|| <ref name="eleccool"/>
|-
|熱解石墨, normal to layers
|3.6
|
|-
| 310不鏽鋼 at 25&nbsp;°C   || 3.352||<ref>{{cite journal  |author1=J. Blumm |author2=A. Lindemann |author3=B. Niedrig |author4=R. Campbell |title=Measurement of Selected Thermophysical Properties of the NPL Certified Reference Material Stainless Steel 310  |journal=[[International Journal of Thermophysics]]  |volume=28 |page=674  |year=2007  |doi= 10.1007/s10765-007-0177-z |issue=2 |bibcode = 2007IJT....28..674B |s2cid=120628607 }}</ref>
|-
| [[英高鎳合金|Inconel 600]] at 25&nbsp;°C  || 3.428|| <ref>{{cite journal |author1=J. Blumm |author2=A. Lindemann |author3=B. Niedrig |title=Measurement of the thermophysical properties of an NPL thermal conductivity standard Inconel 600 |journal=High Temperatures – High Pressures |volume=35/36 |issue=6 |page=621 |year=2003–2007 |url=http://www.perceptionweb.com/abstract.cgi?id=htjr145 |doi=10.1068/htjr145 |access-date=2021-11-07 |archive-date=2015-09-24 |archive-url=https://web.archive.org/web/20150924071018/http://www.perceptionweb.com/abstract.cgi?id=htjr145 |dead-url=no }}</ref> 
|-
| 石英   || 1.4|| <ref name="eleccool"/>
|-
|砂岩
|1.15
|
|-
|冰 at 0&nbsp;°C
|1.02
|
|-
| 二氧化矽 (polycrystalline)  || 0.83||<ref name="eleccool"/> 
|-
|磚塊, common
|0.52
|
|-
|玻璃窗戶
|0.34
|
|-
|磚塊, adobe
|0.27
|
|-
| [[聚碳酸酯|PC塑膠]] (polycarbonate) at 25&nbsp;°C  || 0.144||  <ref  name="HTHP3536pp627">{{cite journal |author1=J. Blumm |author2=A. Lindemann |title= Characterization of the thermophysical properties of molten polymers and liquids using the flash technique |journal=High Temperatures – High Pressures |volume= 35/36 |issue=6 |page= 627 | year= 2003–2007 |doi= 10.1068/htjr144 }}</ref> 
|-
|水 at 25&nbsp;°C
|0.143
|<ref name="HTHP3536pp627" />
|-
|[[聚四氟乙烯|PTFE塑膠]] (Polytetrafluorethylene) at 25&nbsp;°C
|0.124
|<ref>{{cite journal|author1=J. Blumm|author2=A. Lindemann|author3=M. Meyer|author4=C. Strasser|year=2011|title=Characterization of PTFE Using Advanced Thermal Analysis Technique|journal=International Journal of Thermophysics|volume=40|issue=3–4|page=311|bibcode=2010IJT....31.1919B|doi=10.1007/s10765-008-0512-z|s2cid=122020437}}</ref>
|-
| [[聚丙烯|PP塑膠]] (polypropylene) at 25&nbsp;°C  || 0.096|| <ref  name="HTHP3536pp627"/> 
|-
|尼龍
|0.09
|
|-
|橡膠
|0.089 - 0.13
|<ref name="AJP" />
|-
|木材 (黃松)
|0.082
|
|-
| 石蠟 at 25&nbsp;°C  || 0.081||<ref  name="HTHP3536pp627"/> 
|-
| [[聚氯乙烯|PVC塑膠]] (polyvinyl chloride)   || 0.08|| <ref name="eleccool"/>
|-
| 引擎用油 (saturated liquid, 100&nbsp;°C) || 0.0738||
|-
| 酒精 	 || 0.07||<ref name="eleccool"/> 
|}

==參考資料==
{{reflist}}

==参见==
* [[热扩散]]
* [[热容]]
* [[比热容]]
* [[热传导方程式]]
* [[热导率]]

[[Category:物理量]]
[[Category:热传导]]