DISPLAYING OF TRACTOR PERFORMANCE

Transcription

1 International Journal of Mechanical Engineering and Technology (IJMET) Volume 10, Issue 2, February 2019, pp , Article ID: IJMET_10_02_170 Available online at ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed DISPLAYING OF TRACTOR PERFORMANCE Lecturer at Al-Qasim Green University, Iraq ABSTRACT The main purpose of agricultural tractor is required to provide power in a form suitable for variety farm operations. A tractor should be versatile and capable of efficient operations on several kinds of soils under different work conditions. Consequently, tractors can be selected regarding to working environments. Factors such as, maintenance and availability of spare parts, initial cost, driver ability must also be taken into account. The purpose of a drawbar test is to determine performance features of a tractor such as traction efficiency, engine torque, traveling speed and specific fuel consumption at different transmission ratios. It is an involved procedure where the results are presented in graphs and tables that it will be easy understanding and interpretation and understanding. Therefore, there is an essential request to develop a simpler and modern new approaches for results presentation. The objective of this work is to construct and improve a method to simplify the assessment of tractor performance hopping to facilitate tractor selection. Keywords: Tractor, Engine Speed, Torque, Pull, Performance. Cite this Article:, Displaying of Tractor Performance, International Journal of Mechanical Engineering and Technology (IJMET)10(2), 2019, pp INTRODUCTION Tractors are used in agricultural operations, including, irrigation, tracking, logging, land reclamation, and construction. However, numerous factors should be considered before making a selection of a suitable tractor of the requirement applications on farms, such as operational usability, initial and maintenance cost servicing needs, and availability of spare parts (Balasankari, 2003). A farmer is especially concerned with, engine torque, traction horsepower, speed and power take off (P.T.O) shaft (Zoz&Grisso, 2003) editor@iaeme.com

2 Recently, there are many stations of tractors testing in several countries over the world (Kim et a.,2005). A famous testing center is at the University of Nebraske in the U.S.A. In this test, measurements can be made at selected loads and on different kinds of surface with the results stated as individual interpretations in tabular formats. Another famous test station is at the National Institute of Agricultural Engineering (N.I.A.E.), in the United Kingdom, where a comprehensive investigation can be achieved regarding performance on different plowing gradients on different soil conditions. Additionally, there is a British standard test for tractors carried out at Silsoe organization, in England equivalent in scope to the Nebraskan test. Both test techniques have many benefits, however, it may be claimed that test results are of unsatisfactory value, since those tests are not absolutely comprehensive and not easy to follow. Commonl, the tests are not considered by the workers of the tractors (malaria et al., 2013). In order to understand simply the different performance features of an agricultural tractor, the test results should be presented in a perfect and compact way (Stokes&Claar, 2004) The aim of this work is to provide diagrams that are expected to be a simple way can be utilized as a quick reference when choosing an agricultural tractor for a specific task. 2. MATERIAL & METHODS In this examination the drawbar test is occupied with which tractor drawwbar horsepower, traction efficiency, exact fuel consumption, motor torque and speed are viewed as elements of drawbar pull. The" engine speed test" has been considered relating engine horsepower and engine torque as a function of engine speed (Roeber et al.,2017). Calculations are achieved for the above tests and graphs are created from the results obtained for one specification of tractor brand (Zetor 4511). Specifications of tractor Zetor 4511 Number of cylinders 4 Bore/Stroke: 95 x 110 mm Capacity Liters3.1 Normal power H.P. Rated Engine speed R. p. m Maximum Engine speed 2800 Tractor mass (Unloaded) Kg.2100 Wheelbase inches [213 cm] Weight 4630 lbs [2100 kg] Front tire: Rear tire: Overall gear ratios,87.3, 68.4, The equation for an agricultural tractor moving at a non-level surface inclined at angle *ɵ in the transient case (Sumer&Sabnci, 2004)) is: Pt = Pdr +Pj +P r + Q sin ɵ (1) Pt: represent the total traction force Pdr : denote the total drawbar pull Pj : is the total interior force Pr: represent the total rolling resistance Q sin ɵ: denote the tractor weight component parallel to the surface. When the tractor is traveling on a levelled soil in a steady state, then the previous equation can be improved to be: Pt = Pdr+ Pr (2) editor@iaeme.com

3 Displaying of Tractor Performance The value of rolling resistance can be computed from the following relation: Fr = f Q (3) Where f: denotes the coefficient of rolling resistance. Q: is the weight of the tractor When the tractor working under no load condition, then equation (2will be: Pt = Pr (4) Regarding the traction efficiency and force equation, the power developed by the tractor engine in any case is given by the equation below: N e = N m + N s +N r +Ndr (5) Ne: denote the total power developed. Nm: denote the power consumed to overcome losses in transmission and power take off (P.T.O) shaft. Nr: denote the power consumed by rolling resistance. Ndr: denote the power used by load, including power take off shaft. The traction efficiency ɳtr, that is defined as the ratio of power used to do work supplied by the engine, can be create from: ɳt = Ndr/ Ne =( ɳm ) ( ɳs ) (ɳr ) (6) ɳm: denote the efficiency which has been considered the transmission losses. ɳs: denete the efficiency which has been considered the losses because slippage of traction members. ɳr: denote the efficiency which has been considered the losses due to rolling resistance. the traction efficiency was obtained from equation 6 where the value of ɳm, ɳs, ɳr are calculated from the following relationship (Day.et al.,2006) : ɳm = A [ 1 (B. Tn / 100)] (i) ɳs = (1-0.01S) (ii) ɳr = Pdr / (Pr + Pdr) (iii) where, A: is a constant = B: is a constant = Tn: is the engine nominal torque in Kg.m T: is the torque on wheel in Kg.m S: is the slip The overall efficiency can be developed by providing an adequate care and adjustment of the tractor mechanisms, correct selection of loads, speeds, and the proper of ballast (Williams et al.,2005). 3. RESULTS AND DISCUSSION The tractor performance curves consist of two groups. The first one is directly related to drawbar pull, while the other curves are those represent the full consumption, which depend upon the speed of the engine. Also, there are graphs which relate to engine torque as a function of traction and force drawbar pull. The full details on obtaining these performance curves are shown editor@iaeme.com

4 1- Variation of drawbar horsepowr, with drawbar pull. Ndr = Pdr x v/ 270 (7) Pdr: denote the variable drawbar pull in (Kg). V: denote the actual average tractor speed in (Km/ hr), and can be obtained from the following relation (Janulevicius,2018). V = Vc(1-0.1S) (8) S: is the percentage slippage from drawbar test. Ve: is the theoretical traveling speed in (Km/hr) and is calculated from: Ve = 3.6 * π * rw * (n/30 i) (9) rw: is the drive wheel radius in (m) n: is the engine speed in r.p.m. I: is the gear ratio. 2- Variation of tractor speed with drawbar pull. V= Ndr * 270 / pdr (10) 3- Variation of specific fuel consumption with drawbar pull. gdr = 270 * Gf / ( Pdr *V) where, gdr = is the specific fuel consumption with drawbar pull. Gf = is the fuel consumption in (Kg /hr) Pdr = is the drawbar pull in (Kg). 4- Variation of fuel consumption and drawbar pull for each gear ratio. Assuming constant specific fuel consumption. Gf = pdr * V * gdr /270 (11) Since Ndr = Pdr * gdr (12) Ndr: is the drawbar h.p. in (H.P.) 5- Variation of engine torque with engine speed (Sumer&Sabnci.,2004) Te = P/ n (13) Te : is engine torque in (kg.m) P: is engine normal power in (H.P.). 6- Variation of tractor actual travelling speed with engine speed. V = π Dn / 60 (14) Dn: is the wheel diameter in (m). For different transmission ratios, the variation of drawbar horsepower, actual tractor speed, specific fuel consumption, and fuel consumption with a drawbar pull are shown in figures 1,2,3, and4respectively. It should be cited that specific fuel consumption that is calculated by computing fuel consumption with varying drawbar pull (Ismail et al. 2016). Moreover, Variations of engine torque and travelling speed with engine speed are shown in figures 5 and6. The value of Pr is taken from equation (2) by using F = and Q = 2100 Kg. Thus Pr = Pdr Traction torque T = Pdr * D/ (2i) (15) editor@iaeme.com

5 Displaying of Tractor Performance D: is the wheel diameter in (m) i: is the gear reduction ratio. And as a result the variations of traction wheel torque with a drawbar pull have been plotted in figure7. Finally, figure 8 represents the variation of engine power with engine speed. Figure 1 variation of drawbar HP with Drawbar pull for diff rent gear ratios. Figure 2 different gear ratio Actual tractor speed with Drawbar pull for different gear ratio. Figure 3 variation of spicific full consumption with drawbar pull for different gear ratio Figure 4 variation of full consumption with drawbar pull for different gear ratio editor@iaeme.com

6 Figure 5 variation of engine torque with engine Figure 6 variation of tractor traviling with speed engine speed foe different gear ratio Figure 7 variation of tractor wheel torque with drawbar pull for different gear ratio Figure 8 variation of tractor wheel torque with drawbar pull for different gear ratio editor@iaeme.com

7 Displaying of Tractor Performance 4. CONCLUSION To sum up, it is clear to see that improvement of present-day tractor designs are closely allied to progress in operation in operational "Know- how". In other word, skill in driving and tractor management are required. This is because the provisions of better performance and high operational efficiency will be difficult to achieve if there is a low possibility of those advantages being operated by the worker. With the increasing difficulty of the designs and the problems encountered in the training of unskilled worker driving and maintenance, there is a requirement for continuity of design, standardization and simplification. For this purpose, the use of graphs is considered to be useful way. At first glance, the graphs appear to be a complicated diagram, but it is actually quite simple. It represents ten combined factors progress, especially the relationships of speed and torques provided by transmission, in realizing attachment and control, and, in the interchangeability of engines. Furthermore, the diagram can save time and effort required,while comparing performance of different tractors under different conditions and for finally choosing the ideal design of tractors for required operations. The performance can simply be assessed by the diagrams. Moreover, it is possible to establish an advisory service to help the drivers using the tractor for maximum efficiency by understandings of the "diagram" to learn how to use it for determining precise speeds torques and gear ratios for work conditions. Thus, the future developments of the tractor are dependent upon the increase in skills and knowledge on the part of farmers. The better information from the worker and their staff of the factors involved, the more they are expected to claim improvements. As a consequence, it is expected that the "diagrams" will be an answer to some of the farmers requests. REFERENCE [1] Alsuhaibani, S.A., Aljnobi.A.A., Almajhadi.Y.N.(2006)., Tractors and Tillage Implements Performance, CSBE/SCGAB Annual Conference, Edmonton Alberta,Paper No [2] BALASANKARI.K (2003). Investigation on Ergonomics of Tractor Operation as Influenced by Huma Physiology, Vibration and Noise, Tamil Nadu Agricultural University Coimbatore. [3] Day.L., Scott.M., Williams.R., Rechnitzer.G., Walsh.P., Boyle.S.,(2005), Journal of gricultural Safety and Health,(3)11P.P [4] Ismai.A.Jung.W.,Liu,Q.(2016), Accelerated Life Test Design for Tractor Powertrain Front Axle, MATEC Web of Conferences. [5] Janulevicius. A., Pupinis.G., Juostas.A.,(2018), Mathematical Description of Tractor Slippage with Variable Tire Inflation Pressure, Engineering for Rural Development Journal, (23), 5.P.P [6] Kim.K.U.,Bashford.L.L.,Sampson,(2005), Improvement of Tractor Performance, University of Nebraska Lincoln. [7] Molari.G,, Mattetti.M., Perozzi.D., Sereni.E.,(2013), Monitoring of the tractor working parameters from the CAN-Bus, Journal of Agricultural Engineering 2013; volume XLIV(s2):e77,P.P [8] Stokes.J.,Clear.P.,(2004), Evaluating Agricultural Tractor Performance: A Data Envelopment Analysis Approach, in SAE Technical Papers. [9] Sümer.S.k.,Sabanci A., (2005), Effects of Different Tire Configurations on Tractor Performance, Turk J Agric Journal,(5)29.P.P [10] Zoz. F& Graisso.R.(2014), Traction and Tractor Performance, he Society for engineering in agricultural, food, and biological systems, Niles Road, St. Joseph 295, MI USA [11] Tractor Data Zetor at photos.html editor@iaeme.com