Experimental and Numerical Study of the Moisture Loss Rate in Conditioned Alfalfa Stem using Computational Fluid Dynamics

Document Type : Research Article

Authors

• M. Dana
• P. Ahmadi Moghaddam

Department of Mechanical Engineering of Biosystems, Faculty of Agriculture, Urmia University, Urmia, Iran

https://doi.org/10.22067/jam.2021.67096.0

Abstract

Introduction
Today, the development of the livestock industry and feed supply is a vital issue due to the growing world population, the importance of animal protein supply, and the growing requirement for livestock products.
A porous medium refers to a solid-void (pore) space that is occupied by a fluid (gas or liquid). Generally, many of these pores are interconnected which makes the transportation of mass and heat possible through the pores and this contributes to a faster transportation process through the solid matrix. Porosity is the fraction of void space to total volume.
While the pores are large enough, water vapor and air in the porous media can be transported by molecular diffusion. Molecular diffusion of a gas species (e.g., vapor) in a gas mixture (e.g., vapor and air) is described by Fick’s law.
Materials and Methods
In this study, the samples were classified into four categories, including control, 3-impacts (low conditioning), 8-impacts (average conditioning), and 13-impacts (high conditioning). Each category included six samples (50-grams) that were used to measure different characteristics at different stages. All samples were weighed every two hours using a digital scale (0.001 gr precision). The leaf-stem separation force then was extracted using a texture analyzer. All experiments were repeated three times, and finally, the mean of these three repetitions was reported as the final value for the intended parameter.
The geometry of the alfalfa stem was drawn in Gambit software and after meshing and applying boundary conditions; it was transferred to ANSYS Fluent software. Then, while the solver was selected, adjusted under relaxation factors were applied. In the following, mesh independency was checked and the results were reported.
Results and Discussion
To ensure numerical accuracy, the experimental data should be validated with the simulation results. For this purpose, experimental moisture losses were compared to the software results and showed a good agreement. Then, the moisture ratio curves (kinetics of drying) and force-time chart were presented.
The impact of the moisture content of the tissue was evaluated on the value of force per time. Therefore, three samples of alfalfa with different relative humidity in terms of leaf-stem separation force were reported.
The results of the numerical simulations were presented as two main contours: the velocity magnitude and moisture (water vapor) mass fraction. The simulation results were provided for all different modes and compared to the experimental data. Finally, errors between both results were presented in a table.
Conclusion
Regarding the quality and losses of the final product and comparisons between four different modes (control, 3 impacts, 8 impacts, and 13 impacts), the mode with 8 impacts was selected as the best mode.
The Force-time chart illustrated two peaks due to the special multi-layer texture of the alfalfa. Regarding reducing the moisture ratio of the alfalfa as compared to the optimal, the force required to separate the leaves from the alfalfa stem was significantly decreased. Also, a significant increase in the losses was observed for impacts modes higher than 8.

Keywords

• Alfalfa
• Conditioning
• Drying
• Leaf separation force

20.1001.1.22286829.1401.12.3.4.8

Main Subjects

• Modeling

Open Access

©2022 The author(s). This article is licensed under Creative Commons Attribution 4.0 International License (CC BY 4.0), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source.

References

1. Aboltins, A., and P. Kic. 2018. Influence of air velocity on drying dynamics of alfalfa. 17^th International Scientific Conference Engineering for Rural Development 1: 1470-1475.
2. Anderson, J. D. 2009. Basic Philosophy of CFD in Computational Fluid Dynamics. Springer Berlin Heidelberg, Berlin, Heidelberg.
3. Bartzanas, T., D. D. Bochtis, C. G. Sorensen, A. A. Sapounas, and O. Green. 2010. A numerical modeling approach for biomass field drying. Biosystems Engineering 106: 458-469. https://doi.org/10.1016/j.biosystemseng.2010.05.010
4. Che, G., H. J. Wen, L. Wan, Y. R. Qing, and X. Wang. 2015. Kinematic Simulation and Experimental Study on Rotating Air Flow for Drying Alfalfa. Drying Technology 33: 1720-1727. https://doi.org/10.1080/07373937.2015.1026980
5. Datta, A. K. 2007a. Porous media approaches to studying simultaneous heat and mass transfer in food processes. I: Problem formulations. Journal of Food Engineering 80: 80-95. https://doi.org/10.1016/j.jfoodeng.2006.05.013
6. Datta, A. K. 2007b. Porous media approaches to studying simultaneous heat and mass transfer in food processes. II: Property data and representative results. Journal of Food Engineering 80: 96-110. https://doi.org/10.1016/j.jfoodeng.2006.05.012
7. Engels, F. M., and H. G. Jung. 1998. Alfalfa stem tissues: Cell-wall development and lignification. Annals of Botany 82: 561-568. https://doi.org/10.1006/anbo.1998.0705
8. Erriguible, A., P. Bernada, F. Couture, and M. Roques. 2006. Simulation of convective drying of a porous medium with boundary conditions provided by CFD. Chemical Engineering Research and Design 84: 113-23. https://doi.org/10.1205/cherd.05047
9. Farhang, A., A. Hosinpour, H. Darvishi, M. H. Khoshtaghaza, and T. Tavakolli Hashtjin. 2010. Accelerated drying of alfalfa (Medicago sativa) by microwave dryer. Global Veterinaria 5: 158-163.
10. Fasina, O., and S. Sokhansanj. 1995. Modelling the bulk cooling of alfalfa pellets. Drying Technology 13: 1881-1904. https://doi.org/10.1080/07373939508917055
11. Giuberti, G., G. Rocchetti, S. Sigolo, P. Fortunati, L. Lucini, and A. Gallo. 2018. Exploitation of alfalfa seed (Medicago sativa) flour into gluten-free rice cookies: Nutritional, antioxidant and quality characteristics. Food Chemistry 239: 679-687. https://doi.org/10.1016/j.foodchem.2017.07.004
12. Hassanpour, A., A. Modarres Motlagh, M. Esmaiili, and A. Rahmani Didar. 2011. Changes in the mechanical properties of white seedless grapes during different maturity stages. Journal of Food Research 21 (3): 343-355. (In Persian).
13. Hopkins, D. L., E. S. Toohey, M. J. Kerr, and R. Van de Ven. 2011. Comparison of two instruments (G2 Tenderometer and a Lloyd Texture analyser for measuring the shear force of cooked meat. Animal Production Science 511: 71-76. https://doi.org/10.1071/AN10136
14. Ivanov, Y. A., V. Pakhomov, S. Braginets, O. N. Bakhchevnikov, and A. Rukhlyada. 2018. Experimental study on microwave-vacuum drying of alfalfa. Journal of Engineering and Applied Sciences 13 (19): 8019-8024.
15. Jamaleddine, T., and M. Ray. 2010. Application of computational fluid dynamics for simulation of drying processes: A review. Drying Technology 28: 120-54. https://doi.org/10.1080/07373930903517458
16. Kung, L., L. D. Satter, B. A. Jones, K. W. Genin, A. L. Sudoma, G. L. Enders, and H. S. Kim. 1987. Microbial Inoculation of Low Moisture Alfalfa Silage. Journal of Dairy Science 70: 2069-2077. https://doi.org/10.3168/jds.S0022-0302(87)80255-2
17. Naimi, S., G. Shahgholi, A. Rezvanivand Fanaie, and V. Rostampour. 2019. Numerical Study of Wheat Conveying in Separator Cyclone Using Computational Fluid Dynamics. Journal of Agricultural Machinery 11 (2): 231-246. (In Persian). http://doi.org/10.22067/jam.v11i2.79613
18. Nazari G. M., A. Jafari, S. S. Mohtasebi, A. Tabatabaeefar, A. Sharifi, M. J. O’Dogherty, S. Rafiee, and G. Richard. 2008. Effects of moisture content and level in the crop on the engineering properties of alfalfa stems. Biosystems Engineering 101: 199-208. https://doi.org/10.1016/j.biosystemseng.2008.07.006
19. Nazari M., A. Tabatabaeefar, A. Jafari, A. Sharifi, S. Rafiee, and S. S. Mohtasebi. 2009. Influence of moisture content, rate of loading and height regions on tensile strength of alfalfa stems. International Agrophysics 23: 27-30.
20. Patil, R. T., S. Sokhansanj, E. A. Arinze, and G. J. Schoenau. 1993. Methods of expediting drying rates of chopped alfalfa. Transactions of the American Society of Agricultural Engineers 36: 1799-1803.
21. Rezvanivandefanayi, A., and A. M. Nikbakht. 2015. A CFD Study of the Effects of Feed Diameter on the Pressure Drop in Acyclone Separator. International Journal of Food Engineering 11: 71-77. https://doi.org/10.1515/ijfe-2014-0125
22. Rezvanivandefanayi, A., A. Hasanpour, and A. M. Nikbakht. 2019. Study of the vapor thermos-compressor to reduce energy consumption in the sugar production line using Computational Fluid Dynamics. Journal of Agricultural Machinery 10 (2). (In Persian). DOI: 22067/jam.v10i2.76872
23. Rotz, C. A., and Y. Chen. 1985. Alfalfa drying model for the field environment. Transactions of the American Society of Agricultural Engineers 28 (5): 1686-1691. DOI: 13031/2013.32500
24. Sabralilou, B., A. Mohebbi, E. Akbarian, and A. Rezvanicand fanaei. 2019. Aero-acoustical study of axial fan using computational fluid dynamics. Journal of Agricultural Machinery 10 (2): 255-264. (In Persian). DOI: 22067/jam.v10i2.74963
25. Shahbazi, F., and M. Nazari. 2012. Bending and shearing properties of safflower stalk. Journal of Agricultural Science and Technology 14: 743-754.
26. Siles, J. A., P. González-Tello, M. A. Martín, and A. Martín. 2015. Kinetics of alfalfa drying: Simultaneous modelling of moisture content and temperature. Biosystems Engineering 129: 185-196. https://doi.org/10.1016/j.biosystemseng.2014.10.007
27. Tavakoli, H., S. S. Mohtasebi, and A. Jafari. 2009. Effects of moisture content, internode position and loading rate on the bending characteristics of barley straw. Research in Agricultural Engineering. 55: 45-51. https://doi.org/10.17221/26/2008-RAE
28. Wiersma, D. W., P. R. Carter, K. A. Albrecht, and J. G. Coors. 1993. Kernel milkline stage and corn forage yield, quality, and dry matter content. Journal of Production Agriculture 9: 92-99. https://doi.org/10.2134/jpa1993.0094
29. Wu, H. 2004. Alfalfa drying properties and technologies– in Review Nature Science 2: 65-67.
30. Zhao, A., X. XiaoFang, W. YongKang, R. HaiYan, G. G. DengKe, J. JinHua, and S. C. Li. 2018. Measuring texture quality of fresh jujube fruit using texture analyser. Journal of Fruit Science 35: 631-641.
31. Zobeiri, M., V. Rostampour, A. Rezvanivande Fanaei, and A. M. Nikbakht. 2019. Experimental and Numerical investigation of deviation blade effect on sedimentation chamber performance in chickpea harvesting machine. Iran Biosystems Engineering 52. (In Persian). DOI: 22059/ijbse.2020.276317.665166