文摘
英文文摘
List of tables
List of figures
List of abbreviations
CHAPTER Ⅰ：INTRODUCTION
CHAPTER Ⅱ：LITERATURE REVIEWS
CHAPTER Ⅲ：MATERIALS AND METHODS
3.1.Objective of the research
3.2.Equipment and Instruments Used in the Experiments
3.2.1.Test stand with camera system
3.2.2.The 2BFQ-4 combined planter
3.2.3.Physical characteristics of wheat kernels
3.2.4.Determination of angle repose
3.3.Modification of the Pneumatic Metering Device for Rapeseed
3.3.1.The rapeseed metering device
3.3.2.Operating principle of the rapeseed metering device
3.3.3.Modifications of the rapeseed metering device to suit wheat
3.3.4.Determination of theoretical and practical seed spacing
3.3.5.Suggested seed plates for wheat
2.3.6.Testing a new seed plates
3.3.7.New shield and plates for the modified rapeseed metering device used for wheat
3.3.8.Field experiment with modified seeder
3.4.Introduction to ANSYS-CFX
3.5.Simulation process
3.6.The results of ANSYS simulation
3.6.1.Simulation of designed pressure inlet and seed plate under different levels of negative pressure
3.6.2.Comparison between cylindrical and revolved pressure inlet using a seed plate with 1.8mm under 2.5 kPa negative pressure
3.6.3.Simulation of different pressure inlets and different seed holes with 2.5 kPa negative pressure
3.7.Design of the Precision Metering Device for Wheat
3.7.1.Structure of the wheat seeder
3.7.2.Operating principles
3.8.Determination of seed holding ratio
3.9.Dynamic and kinematic analysis
3.10.The deficiency of the seed inlet and seed tube
3.11.Results of the vertical seed tube
3.12.Reducing the size of the cut-off device and designing a new shield with hooked seed tube
3.12.1.Laboratory testing using the new shield with hooked seed tube
3.12.2.Determination of QFI，MULI，MISI and KPM
3.12.3.Field experiment using the new shield with hooked seed tube
CHAPTER Ⅳ：RESULTS AND DISCUSSION
4.1.The results of laboratory testing using the test stand with camera system
4.1.1.The effect of rotating speed(RS)and negative pressure(NP)on quality of feed index(QFI)，multiple index(MULI)and miss index(MISI)
4.1.2.The relationship between QFI，MULI，MISI，RS and NP
4.1.3.The effect of rotating speed(RS)and negative pressure(NP)on number of kernels per meter(KPM)
4.1.4.The significance and correlations between QFI，MULI，MISI，KPM RS and NP
4.2.The results of field experiment
CHAPTERV：CONCLUSIONS AND RECOMMENDATIONS
5.1.Conclusions
5.2.Recommendations
Acknowledgements
REFERENCES
APPENDICES
Appendix A
Appendix B
Appendix C
Appendix D
Appendix E
Appendix F
Appendix G
Appendix H
Appendix I
