The Effect of Surface Wettability on the Defrost Process (eBook)

Yang Liu, is a senior engineer at Tsinghua-Zhongcheng United Research Center on Intelligent manufacturing.  She received her PhD in mechanical engineering at University of Minnesota in 2017.  Prior to studying at University of Minnesota, she worked as a gas turbine application engineer and field service engineer at GE China for five years.  Her current work is on the vibration measurement and control.

Preface 6
Contents 8
Nomenclature 10
Greek Symbols 11
Subscripts 12
Chapter 1: Introduction 13
Chapter 2: Prior Research 15
2.1 Frost Formation 15
Frost Nucleation 15
Experiments and Correlations 16
Analytical Models 18
Effects of Surface Wettability 19
2.2 The Defrost Process 22
Effect of Surface Wettability 22
Frost Release and Condensate Retention 24
Analytical Models 28
Ice Adhesion 31
2.3 Summary 33
Chapter 3: A Model of the Defrost Process 34
3.1 General Description of the Melting Model 34
3.2 Meltwater Absorption 36
3.3 Meltwater Accumulation 39
3.4 Meltwater Draining 41
3.5 Defrost Time and Efficiency 44
3.6 Slumping Criteria 44
Force Balance in the Absorption Process 46
The Force Balance During Meltwater Accumulation 47
The Force Balance During Meltwater Draining 50
Chapter 4: Solution Methods 51
4.1 Absorption 51
4.2 Accumulation 53
4.3 Draining 53
4.4 Slumping Criteria 56
Chapter 5: Experimental Design 59
5.1 Apparatus 59
5.2 Design Analysis 60
Chamber Energy Balance 61
Heat Transfer Coefficient on the Test Surface and Frost 62
Heat Flux at the Test Surface 65
Heat Sink 67
Capacity of the Thermoelectric Module 67
5.3 Data Acquisition and Uncertainty Estimates 69
Uncertainty Estimates 70
5.4 Surface Preparation and Characterization 71
Chapter 6: Results 74
6.1 Analytical and Numerical Results 74
Slumping Criterion 86
6.2 Experimental Results 91
6.3 Comparison of Predictions and Measurements 108
Chapter 7: Conclusion 113
7.1 Future Research Pathways 115
Instruments and Precision 117
Slumping Image 119
References 120