| Titre : | Effect of the artificial roughness dispositions on the thermal exchanges in a flat solar collector |
| Auteurs : | charaf eddine Bensaci, Auteur ; Abdelhafid Moummi, Directeur de thèse |
| Type de document : | Monographie imprimée |
| Editeur : | Biskra [Algerie] : Université Mohamed Kheider, 2021 |
| Langues: | Français |
| Mots-clés: | Solar air heater ; Baffles ; CFD simulation ; Local convective heat transfer coefficient ; Thermo-hydraulic performance. |
| Résumé : |
In this thesis, a numerical and experimental study of different position of the baffles in a
solar air heater have been presented in order to improve its thermal and hydraulic performance. The numerical study was performed on four cases corresponding to different placements of baffles, where the experimental model of the solar air heater was designed, manufactured and used for the validation of the numerical model. The CFD simulations have been performed by ANSYS FLUENT 15.0. Based on the obtained results, the new baffle placements show that effective thermo-hydraulic performance is not just a function of the shape or changes in the geometric parameters of the baffles. The correct placement of baffles dramatically improves the thermohydraulic performance of solar air heaters. The effect of baffle positions on local convective heat transfer coefficients has been discussed |
| Sommaire : |
TABLE OF CONTENTS
Table of Contents…………………………………………………………………………………………………..............i List of Figures…………………………………………………………………………………………………………………iii List of Tables…………………………………………………………………………………………………………………..vi Nomenclature………………………………………………………………………………………………………………...vii GENERAL INTRODUCTION ........................................................................................... 1 CHAPTER I: BACKGROUND AND LITERATURE REVIEW I.1. Introduction............................................................................................................ 5 I.1.1. Active techniques............................................................................................ 6 I.1.2. Passive techniques........................................................................................... 7 I.1.3. Compound techniques..................................................................................... 8 I.2. Methodology of artificial roughness geometry...................................................... 8 I.3. The used artificial roughness in solar air heater .................................................... 9 I.3.1. The ribs.......................................................................................................... 10 I.3.2. The baffles..................................................................................................... 19 I.4. Performance analysis of solar air heater.............................................................. 31 I.4.1. Thermal characteristics ................................................................................. 31 I.4.2. Hydraulic characteristics............................................................................... 32 I.4.3. Thermohydraulic characteristics................................................................... 32 I.5. Conclusion ........................................................................................................... 33 CHAPTER II: EXPERIMENTAL STUDY II.1. Introduction.......................................................................................................... 35 II.2. Experimental model design.................................................................................. 35 II.2.1. Description of cases ...................................................................................... 37 II.3. Experimental Procedure, Measurement and heat transfer calculation................. 39 II.3.1. Temperature measurement ............................................................................ 39 II.3.2. Solar radiation measurement......................................................................... 42 ii II.3.3. Air flow rate measurement............................................................................ 42 II.3.4. Pressure measurement................................................................................... 43 II.3.5. Uncertainty .................................................................................................... 44 II.3.6. Heat transfer calculation ............................................................................... 44 II.4. Results and discussion ......................................................................................... 46 II.5. Conclusion ........................................................................................................... 55 CHAPTER III: NUMERICAL STUDY III.1. Introduction.......................................................................................................... 57 III.2. Numerical methodology....................................................................................... 57 III.2.1. Geometry and cases descriptions.................................................................. 59 III.2.2. Mesh generation ............................................................................................ 60 III.2.3. Solver ............................................................................................................ 63 III.2.4. Turbulence models........................................................................................ 68 III.2.5. Boundary conditions ..................................................................................... 72 III.2.6. Validation of the numerical model................................................................ 73 III.3. Conclusion ........................................................................................................... 77 CHAPTER IV: RESULTS AND DISCUSSION IV.1. Introduction.......................................................................................................... 79 IV.2. Comparison of numerical results and experimental data..................................... 79 IV.3. Assessment of heat transfer coefficients.............................................................. 80 IV.4. Assessment of thermal efficiency ........................................................................ 87 IV.5. Assessment of friction factor ............................................................................... 89 IV.6. Assessment of the thermo-hydraulic performance factor.................................... 90 IV.7. Conclusion ........................................................................................................... 91 GENERAL CONCLUSION…………………………………………………………………..92 REFERENCES……………….......................................................................................... 96 APPENDICES………………….…................................................................................105 |
Disponibilité (1)
| Cote | Support | Localisation | Statut | Emplacement | |
|---|---|---|---|---|---|
| TH/1072 | Thèse de doctorat | BIB.FAC.ST. | Empruntable |
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