{"title":"带翅片的开放式空腔中的混合对流传热","authors":"Mohammed Abu-Ghurban, Khaled Al-Farhany","doi":"10.1002/htj.23128","DOIUrl":null,"url":null,"abstract":"<p>This work numerically explores the mixed convective heat transfer in an open square enclosure containing conducting fins fixed to the heated vertical wall. This kind of work with fins has enormous potential due to its applications in research, engineering, and current industries. Therefore, the current work is highly significant to understand the impact of mixed convection. The external flow enters from the hole in the bottom wall and leaves from the hole in the upper wall. The left vertical wall of the enclosure is heated isothermally, and the fins are attached to the heated walls at a uniform height. Both the upper and lower walls are adiabatic, whereas the right sidewall is at a lower temperature. The non-dimensional transport equations are resolved by using the finite element method. The study is accomplished for the wide control variables range, such as Reynolds number (50 ≤ <i>Re</i> ≤ 200), Richardson's number (0.1 ≤ <i>Ri</i> ≤ 10), the length of the fins (<i>L</i><sub><i>f</i></sub> = 0.2, 0.4, and 0.6), the size of the outlet opening (<i>W</i><sub><i>out</i></sub> = 0.1, 0.2, and 0.3), and the gaps in between the outlet hole and left heated wall (<i>S</i> = 0, 0.45, and 0.9). The results show that the thermal performance of the open enclosure is meaningfully affected by the control parameters. The maximum and minimum heat transfer happens when the position of the outlet opening is at the left (<i>S</i> = 0) and right (<i>S</i> = 0.9), respectively. The heat transfer improves by raising the <i>Ri</i> and <i>Re</i>, whereas increasing the fin's length and distance between the outlet opening and left wall reduces heat transfer significantly. The <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>N</mi>\n \n <msub>\n <mi>u</mi>\n \n <mi>avg</mi>\n </msub>\n </mrow>\n </mrow>\n </semantics></math> rises 13% with a decrease in the fin's length <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mo>(</mo>\n \n <msub>\n <mi>L</mi>\n \n <mi>f</mi>\n </msub>\n \n <mo>)</mo>\n </mrow>\n </mrow>\n </semantics></math> from 0.6 to 0.2 at <i>Re</i> = 200, <i>S</i> = 0 due to the improvement of the convection on the heated wall. Also, <span></span><math>\n <semantics>\n <mrow>\n \n <mrow>\n <mi>N</mi>\n \n <msub>\n <mi>u</mi>\n \n <mi>avg</mi>\n </msub>\n </mrow>\n </mrow>\n </semantics></math> increases by 15% when <i>Ri</i> increases from 1 to 9.</p>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"53 8","pages":"4169-4196"},"PeriodicalIF":2.8000,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Mixed convective heat transfer in an open cavity with fins\",\"authors\":\"Mohammed Abu-Ghurban, Khaled Al-Farhany\",\"doi\":\"10.1002/htj.23128\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>This work numerically explores the mixed convective heat transfer in an open square enclosure containing conducting fins fixed to the heated vertical wall. This kind of work with fins has enormous potential due to its applications in research, engineering, and current industries. Therefore, the current work is highly significant to understand the impact of mixed convection. The external flow enters from the hole in the bottom wall and leaves from the hole in the upper wall. The left vertical wall of the enclosure is heated isothermally, and the fins are attached to the heated walls at a uniform height. Both the upper and lower walls are adiabatic, whereas the right sidewall is at a lower temperature. The non-dimensional transport equations are resolved by using the finite element method. The study is accomplished for the wide control variables range, such as Reynolds number (50 ≤ <i>Re</i> ≤ 200), Richardson's number (0.1 ≤ <i>Ri</i> ≤ 10), the length of the fins (<i>L</i><sub><i>f</i></sub> = 0.2, 0.4, and 0.6), the size of the outlet opening (<i>W</i><sub><i>out</i></sub> = 0.1, 0.2, and 0.3), and the gaps in between the outlet hole and left heated wall (<i>S</i> = 0, 0.45, and 0.9). The results show that the thermal performance of the open enclosure is meaningfully affected by the control parameters. The maximum and minimum heat transfer happens when the position of the outlet opening is at the left (<i>S</i> = 0) and right (<i>S</i> = 0.9), respectively. The heat transfer improves by raising the <i>Ri</i> and <i>Re</i>, whereas increasing the fin's length and distance between the outlet opening and left wall reduces heat transfer significantly. The <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>N</mi>\\n \\n <msub>\\n <mi>u</mi>\\n \\n <mi>avg</mi>\\n </msub>\\n </mrow>\\n </mrow>\\n </semantics></math> rises 13% with a decrease in the fin's length <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mo>(</mo>\\n \\n <msub>\\n <mi>L</mi>\\n \\n <mi>f</mi>\\n </msub>\\n \\n <mo>)</mo>\\n </mrow>\\n </mrow>\\n </semantics></math> from 0.6 to 0.2 at <i>Re</i> = 200, <i>S</i> = 0 due to the improvement of the convection on the heated wall. Also, <span></span><math>\\n <semantics>\\n <mrow>\\n \\n <mrow>\\n <mi>N</mi>\\n \\n <msub>\\n <mi>u</mi>\\n \\n <mi>avg</mi>\\n </msub>\\n </mrow>\\n </mrow>\\n </semantics></math> increases by 15% when <i>Ri</i> increases from 1 to 9.</p>\",\"PeriodicalId\":44939,\"journal\":{\"name\":\"Heat Transfer\",\"volume\":\"53 8\",\"pages\":\"4169-4196\"},\"PeriodicalIF\":2.8000,\"publicationDate\":\"2024-07-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Heat Transfer\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/htj.23128\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"THERMODYNAMICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Heat Transfer","FirstCategoryId":"1085","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/htj.23128","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"THERMODYNAMICS","Score":null,"Total":0}
引用次数: 0
摘要
本研究以数值方法探讨了在一个开放式方形外壳中的混合对流传热问题,该外壳包含固定在受热垂直壁上的导电翅片。由于翅片在研究、工程和当前工业中的应用,这种工作具有巨大的潜力。因此,目前的工作对于了解混合对流的影响意义重大。外部气流从下壁上的孔进入,从上壁上的孔流出。机箱左侧垂直壁进行等温加热,翅片以均匀的高度附着在加热壁上。上下壁都是绝热的,而右侧壁的温度较低。采用有限元法求解非维度传输方程。研究的控制变量范围很宽,如雷诺数(50 ≤ Re ≤ 200)、理查森数(0.1 ≤ Ri ≤ 10)、翅片长度(Lf = 0.2、0.4 和 0.6)、出口开口尺寸(Wout = 0.1、0.2 和 0.3)以及出口孔与左侧加热壁之间的间隙(S = 0、0.45 和 0.9)。结果表明,控制参数对开放式箱体的热性能有显著影响。当出风口位置位于左侧(S = 0)和右侧(S = 0.9)时,传热量分别最大和最小。提高 Ri 和 Re 值可改善传热效果,而增加翅片长度和出口开口与左壁之间的距离则会显著降低传热效果。在 Re = 200、S = 0 条件下,翅片长度从 0.6 减小到 0.2 时,传热系数上升了 13%,这是因为受热壁上的对流得到了改善。此外,当 Ri 从 1 增加到 9 时,热传导也增加了 15%。
Mixed convective heat transfer in an open cavity with fins
This work numerically explores the mixed convective heat transfer in an open square enclosure containing conducting fins fixed to the heated vertical wall. This kind of work with fins has enormous potential due to its applications in research, engineering, and current industries. Therefore, the current work is highly significant to understand the impact of mixed convection. The external flow enters from the hole in the bottom wall and leaves from the hole in the upper wall. The left vertical wall of the enclosure is heated isothermally, and the fins are attached to the heated walls at a uniform height. Both the upper and lower walls are adiabatic, whereas the right sidewall is at a lower temperature. The non-dimensional transport equations are resolved by using the finite element method. The study is accomplished for the wide control variables range, such as Reynolds number (50 ≤ Re ≤ 200), Richardson's number (0.1 ≤ Ri ≤ 10), the length of the fins (Lf = 0.2, 0.4, and 0.6), the size of the outlet opening (Wout = 0.1, 0.2, and 0.3), and the gaps in between the outlet hole and left heated wall (S = 0, 0.45, and 0.9). The results show that the thermal performance of the open enclosure is meaningfully affected by the control parameters. The maximum and minimum heat transfer happens when the position of the outlet opening is at the left (S = 0) and right (S = 0.9), respectively. The heat transfer improves by raising the Ri and Re, whereas increasing the fin's length and distance between the outlet opening and left wall reduces heat transfer significantly. The rises 13% with a decrease in the fin's length from 0.6 to 0.2 at Re = 200, S = 0 due to the improvement of the convection on the heated wall. Also, increases by 15% when Ri increases from 1 to 9.