Revue Générale de Thermique最新文献_第10页

Equipments/Matériels 舾装/材料

Revue Générale de Thermique Pub Date : 1998-06-01 DOI: 10.1016/S0035-3159(98)90043-5

引用次数: 0

Revue Générale de Thermique Pub Date : 1998-06-01 DOI: 10.1016/S0035-3159(98)90042-3

引用次数: 0

Étude des transferts couplés par convection et rayonnement dans un écoulement de type couche limite de fluide thermodépendant non gris: application d'un modèle statistique à bandes étroites 非灰色热模拟流体边层流中对流和辐射耦合传输的研究:窄波段统计模型的应用

Revue Générale de Thermique Pub Date : 1998-06-01 DOI: 10.1016/S0035-3159(98)80065-2

Faycal Ben Nejma, Mohamed-Sassi Radhouani

引用次数: 1

Modélisation d'un échangeur de chaleur compact à courants croisés séparés par des couches de matériau à changement de phase 由相变材料层分隔的紧凑交叉流热交换器的建模

Revue Générale de Thermique Pub Date : 1998-06-01 DOI: 10.1016/S0035-3159(98)80067-6

Hamid El Qarnia, Marcel Lacroix

{"title":"Modélisation d'un échangeur de chaleur compact à courants croisés séparés par des couches de matériau à changement de phase","authors":"Hamid El Qarnia, Marcel Lacroix","doi":"10.1016/S0035-3159(98)80067-6","DOIUrl":"10.1016/S0035-3159(98)80067-6","url":null,"abstract":"<div>A mathematical model was developed to predict the thermal behaviour of a crossflow compact heat exchanger with layers of phase change material (PCM) operating under winter conditions. The model is validated and a parametric study is conducted to determine the design and operating conditions that promote condensation and may lead eventually to the frosting of the exchanger. The transient and steady-state thermal efficiency of the exchanger are also predicted as a function of the number of thermal units NTUf, of the ratio of the products of the mass flow rate by the heat capacity on the cold and hot sides C and of the Biot number Bi. Results indicate that for Bi = 0.6 (which corresponds to a 3 mm thick PCM layer), condensation occurs when NTUf ≥ 2.0 for C = 1.0 and when NTUf ≥ 5.0 for C = 0.5. If the thickness of the PCM layer increases, condensation is avoided and the duration of the heat recovery period is prolonged. At the same time however, the steady state thermal efficiency diminishes. A heat exchanger for which Bi = 0.6, C = 0.5 and NTUf = 4.0 appears to be a good compromise for acceptable heat recovery and efficiency. In this case, the heat recovery period lasts 1.6 h and the steady state thermal efficiency levels off at 64 %.</div>","PeriodicalId":101133,"journal":{"name":"Revue Générale de Thermique","volume":"37 6","pages":"Pages 514-524"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0035-3159(98)80067-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73315158","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Referees 1997/Comité de lecture RGT 1997 裁判员1997/ RGT阅读委员会1997

Revue Générale de Thermique Pub Date : 1998-06-01 DOI: 10.1016/S0035-3159(98)90041-1

引用次数: 0

Books/Livres Books书籍/

Revue Générale de Thermique Pub Date : 1998-06-01 DOI: 10.1016/S0035-3159(98)90044-7

引用次数: 0

Thermal control of electronic equipment by heat pipes 热管对电子设备的热控制

Revue Générale de Thermique Pub Date : 1998-05-01 DOI: 10.1016/S0035-3159(98)80089-5

Manfred Groll , Marcus Schneider , Valérie Sartre , Mohamed Chaker Zaghdoudi , Monique Lallemand

{"title":"Thermal control of electronic equipment by heat pipes","authors":"Manfred Groll , Marcus Schneider , Valérie Sartre , Mohamed Chaker Zaghdoudi , Monique Lallemand","doi":"10.1016/S0035-3159(98)80089-5","DOIUrl":"10.1016/S0035-3159(98)80089-5","url":null,"abstract":"<div>In the frame of the BRITE-EURAM european programme (KHIEPCOOL project), a literature survey on the main heat pipe and micro heat pipe technologies developed for thermal control of electronic equipment has been carried out. The conventional heat pipes are cylindrical, flat or bellow tubes, using wicks or axial grooves as capillary structures. In the field of micro heat pipes, three and four corner tubes have been developed. The pipes are mounted on single chips, in-line chip arrays or integrated into the component interconnection substrate. The best performances were achieved with Plesch's axially grooved flat miniature heat pipe [1], which is able to transfer a heat flux of about 60 W·cm−2. Theoretical models have shown that the performance of micro heat pipe arrays increase with increasing tube diameter, decreasing tube length and increasing heat pipe density. The heat pipe technologies are classified and compared according to their geometry and location in the system. A list of about 150 references, classified according to their subjects, is presented.</div>","PeriodicalId":101133,"journal":{"name":"Revue Générale de Thermique","volume":"37 5","pages":"Pages 323-352"},"PeriodicalIF":0.0,"publicationDate":"1998-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0035-3159(98)80089-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85012688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 88

Interaction d'un écoulement de thermosiphon avec un panache thermique à symétrie axiale: étude expérimentale 热虹吸流与轴向对称热羽流的相互作用:实验研究

Revue Générale de Thermique Pub Date : 1998-05-01 DOI: 10.1016/S0035-3159(98)80100-1

Ahmedou Ould Mohamed Mahmoud, Rejeb Ben Maad, Ali Belghith

{"title":"Interaction d'un écoulement de thermosiphon avec un panache thermique à symétrie axiale: étude expérimentale","authors":"Ahmedou Ould Mohamed Mahmoud, Rejeb Ben Maad, Ali Belghith","doi":"10.1016/S0035-3159(98)80100-1","DOIUrl":"10.1016/S0035-3159(98)80100-1","url":null,"abstract":"<div>The present work reports an experimental study of a thermosiphon effect on an axisymmetric thermal plume. An experimental apparatus composed of a circular disc heated at constant temperature was set up. The disc is placed at the entrance to an open-ended vertical cylinder of larger diameter. Thermal radiation emitted by the hot disc heats the cylinder wall. The heating of fluid to the cylinder-inlet is the cause of the thermosiphon effect around the thermal plume. First, we studied the flow generated by the thermal plume. The analysis of the average fields of velocity and temperature shows that the structure of a thermal plume generated by a hot obstacle is affected by the characteristics of the main flow around this obstacle. Furthermore, these results allowed us to rediscover the two classical zones which constitute a thermal plume. Secondly, we studied the thermosiphon effect on the thermal plume development. The average fields evolution of velocity and temperature as well as the flow visualization show the existence of three different zones. The first zone of the plume air feeding is characterized by the dynamic and thermal profiles in three extrema structures. These extrema disappear in the second zone where the profiles present only one maximum. In the last zone, the profiles are flattened and self-similar. Thus, the turbulence is fully developed. However, one observes an improvement in the amount of energy absorbed by the fluid and an increase in the flow rate inside the cylinder. A flow visualization with laser plan allowed us to show that the position of the vertical cylinder around the hot disc affects the flow structure plume and causes the appearance of a new zone at the entrance to the system. However, the analysis of the fluctuating fields related to two studied cases shows that the thermosiphon effect has an important influence on the turbulent intensity structure of the flow evolution.</div>","PeriodicalId":101133,"journal":{"name":"Revue Générale de Thermique","volume":"37 5","pages":"Pages 385-396"},"PeriodicalIF":0.0,"publicationDate":"1998-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0035-3159(98)80100-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89119926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 17

A new viscous sublayer influx (VSI) concept for near-wall turbulent momentum, heat and mass transfer 一个新的粘性亚层内流(VSI)概念，用于近壁湍流动量、传热和传质

Revue Générale de Thermique Pub Date : 1998-05-01 DOI: 10.1016/S0035-3159(98)80090-1

Sönke Bröcker

{"title":"A new viscous sublayer influx (VSI) concept for near-wall turbulent momentum, heat and mass transfer","authors":"Sönke Bröcker","doi":"10.1016/S0035-3159(98)80090-1","DOIUrl":"10.1016/S0035-3159(98)80090-1","url":null,"abstract":"<div>This paper presents a new viscous sublayer influx (VSI) concept to describe near-wall turbulent momentum, heat and mass transfer. Based on visual studies, this concept takes account of a viscous sublayer adjacent to the wall, which is not directly affected by the bursts occurring in the wall region. Fluid penetrates only due to a wallward flow into this viscous sublayer. Thus, in contrast to the known surface renewal concept, the new VSI concept is consistent with visual flow studies and, in addition, makes it possible to meet the experimentally found limiting condition Sh ∼ 3√ScSc→∞ for mass transfer. In this work, two models have been developed from the new VSI concept. The simplified viscous sublayer influx model follows the known models in literature and provides analytical equations for the profiles in the wall region. This model gives an explanation for the varying experimental results on the time intervals between successive bursts and predicts them in quantity by using measured Sherwood numbers at very high Schmidt numbers. The second, more detailed viscous sublayer influx model approximates the wallward flow in the viscous sublayer with a spherical stagnation point flow. The profiles are calculated from two ordinary differential equations. Using measured Sherwood numbers at very high Schmidt numbers, this model provides normal velocity fluctuations at the wall that agree well with experimental data. Furthermore, both models provide axial velocity fluctuations near the wall and Nusselt/Sherwood numbers in the range 0.5 ≤ Pr, Sc≤ 105 that both correspond with experimental data.</div>","PeriodicalId":101133,"journal":{"name":"Revue Générale de Thermique","volume":"37 5","pages":"Pages 353-370"},"PeriodicalIF":0.0,"publicationDate":"1998-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0035-3159(98)80090-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81875144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Distribution des températures à l'intérieur d'un jet de gaz chaud injecté dans un liquide 注入液体的热气体射流内的温度分布

Revue Générale de Thermique Pub Date : 1998-05-01 DOI: 10.1016/S0035-3159(98)80101-3

Francis Roger , Abdelaziz Benbarkat , Laurent Gbahoué , Jean-Louis Carreau

引用次数: 0