Browse

Analysis of Relative Humidity Effects on Ejector Performance

DC Field Value Language
dc.contributor.advisor송성진-
dc.contributor.author이호채-
dc.date.accessioned2017-10-27T16:33:02Z-
dc.date.available2017-10-27T16:33:02Z-
dc.date.issued2017-08-
dc.identifier.other000000145351-
dc.identifier.urihttps://hdl.handle.net/10371/136707-
dc.description학위논문 (박사)-- 서울대학교 대학원 공과대학 기계항공공학부, 2017. 8. 송성진.-
dc.description.abstractPumping in ejectors is a measure of how much the secondary fluid is entrained by the high momentum primary flow and is one of the crucial performance indices. In the fuel recirculation system of fuel cells, the entrained secondary fluid contains water vapor due to the over-supplied hydrogen, making the secondary fluid humid. In such cases, the relative humidity of the secondary fluid alters the fluid properties of the mixed flow. This study examines such effects of relative humidity on ejector. A new analytical model has been developed, and series of measurements has been conducted to validate the models prediction. The present results demonstrate that higher relative humidity of the secondary fluid reduces pumping in an ejector. During the mixing process of the two fluids, condensation releases heat, increasing the ejector operating temperature. Thus, secondary flow density is decreased, and pumping is lowered.-
dc.description.tableofcontentsChapter 1. Introduction 1
1.1 Background and motivation 1
1.2 Research objectives 7
1.3 Approach and scope 8
1.4 Thesis organization 9
Chapter 2. One-dimensional Analysis of an Ejector 10
2.1 Introduction 10
2.1.1 Condensation effect 15
2.1.2 Change of thermo-physical properties of humid air 17
2.2 Modeling procedure 22
2.3 Conclusions 29
Chapter 3. Measurement of Pumping Degradation due to Humidity 31
3.1 Introduction 31
3.2 Experiment of an ejector with humid secondary flow 33
3.2.1 Experiment setup 33
3.2.2 Ejector Design 50
3.2.3Uncertainty analysis 63
3.3 Test result 65
3.4 Conclusions 71
Chapter 4. Modelling Result and Discussion 72
4.1 Ejector pumping and condensation 72
4.2 Effect of secondary temperature on ejector performance 76
4.3 Effect of pressure drop due to condensation 81
4.4 Variation of thermos-physical properties 83
4.5 Ejector characteristics 86
4.6 Conclusions 90
Chapter 5. Summary and conclusions 92
References 95
Abstract (Korean) 100
-
dc.formatapplication/pdf-
dc.format.extent2839845 bytes-
dc.format.mediumapplication/pdf-
dc.language.isoen-
dc.publisher서울대학교 대학원-
dc.subjectEjector performance-
dc.subjectRelative humidity-
dc.subjectCondensation-
dc.subjectFuel cell automobile-
dc.subject.ddc621-
dc.titleAnalysis of Relative Humidity Effects on Ejector Performance-
dc.typeThesis-
dc.description.degreeDoctor-
dc.contributor.affiliation공과대학 기계항공공학부-
dc.date.awarded2017-08-
Appears in Collections:
College of Engineering/Engineering Practice School (공과대학/대학원)Dept. of Mechanical Aerospace Engineering (기계항공공학부)Theses (Ph.D. / Sc.D._기계항공공학부)
Files in This Item:
  • mendeley

Items in S-Space are protected by copyright, with all rights reserved, unless otherwise indicated.

Browse