Computer Simulation for Haulage Performance of Power Tiller
The presence of a large number of marginal and small land holdings in India has rendered the power tiller to be the most suitable farm equipment for field operations, in view of its compact size, profitability and versatility, but the transport work which is also required to carry the farm produce is yet to be proved. Keeping these in mind, user friendly software was developed for predicting the haulage performance of power tiller to meet requirements in educational and research organizations. The developed software requires input parameters such as power tiller, trolley and operating conditions. The developed software was validated by conducting experiments with a 6.7 kW power tiller using a suitable trolley on tarmacadam road at various payloads and road slopes. The draft, slip, fuel consumption and speed were measured and other haulage performance parameters were calculated based on measured values to validate the developed software. The results simulated by software indicate lower draft and slip in the range of 1-23 and 2-9% with respect to the experimental data, however, higher transport productivity was in the range of 3-12%.
A program in Visual Basic for predicting haulage and field performance of 2WD tractors
A tractor drawbar performance program that predicts the performance of two-wheel-drive (2WD) tractors for haulage as well as field operations for both bias-ply and radial-ply tyres is developed to meet user requirements in educational and research organizations. The program is written in Visual Basic programming language. The program provides an intuitive user interface by linking databases such as tractor specifications, tyre data, implement and trailer specifications and traction equation coefficients to predict the performance of a selected tractor model. The program has been proven to be user friendly and efficient for various field operations under frictional-cohesive soils.
Tractors and Their Power Units
1 Development of the Tractor.- Tractor Types.- Some World Variations in Tractors.- Functions of a Farm Tractor.- Sources of Energy.- Energy Conversion Devices.- The Future Engine.- Trends in Tractor Design.- 2 Thermodynamic Principles of Internal-Combustion Engines.- Specific Heat.- Entropy.- Energy Changes.- Constant-Volume Changes.- Constant-Pressure Changes.- Isothermal Changes.- Adiabatic or Constant-Entropy Changes.- General or Polytropic Changes.- Changes in an Adiabatic Expansion of a Perfect Gas.- Determination of the Value of n from an Actual Compression Line.- Equations for Nonflow Processes.- 3 Internal-Combustion Engine Cycles.- Simplifying Assumptions.- The Ideal Air-Standard Otto Cycle.- The Ideal Air-Standard Diesel Cycle.- Actual Cycles and Causes for Deviation from the Ideal.- 4 Fuels and Combustion.- Sources of Fuels.- Chemical Composition of Petroleum.- Petroleum Refining.- Combustion.- Gasoline Tests and Their Significance.- Antiknock Quality.- Factors Affecting the Octane Number Requirement.- Volatility.- Distillation.- Reid Vapor Pressure Test.- Sulfur Content.- Corrosion Test.- Gum Content.- Gravity.- Heating Values.- Gasoline Additives.- Diesel Fuel Tests and Their Significance.- Cetane Number.- Heating Value of Diesel Fuel.- Viscosity.- Carbon Residue.- Flash Point.- Pour Point and Cloud Point.- Ash Content.- Diesel Fuel Additives.- Alternate Fuels.- 5 Engine Design.- Engine Design-General.- Stroke-to-Bore Ratio.- Crankshafts and Firing Orders.- Tractor Engine.- Valve Design.- Valve Materials, Design, and Application.- Valve Timing.- Valve Clearance Adjustment.- Valve Seats.- Valve-Opening Area.- Cams.- Combustion Chamber Design.- Effect of Compression Ratio.- Piston Crank Kinematics.- Inertia Force of Connecting Rod.- Inertia Force of Single-Cylinder Engines.- Crank Effort.- Flywheels.- Balance of Single-Cylinder Engines.- Balance of Multicylinder Engines.- Principles of CI Engine Operation.- Construction of Diesel Engines.- Combustion Chamber Design.- Fuel-Injection Systems.- Fuel Injectors.- Turbochargers.- Matching of Turbocharger to Engine.- Aftercooling.- Engine Noise.- 6 Electrical Systems.- Battery.- Starting Motor.- Electrical Charging.- Battery Ignition System with Breaker Points.- Magneto Ignition System.- Ignition Timing.- Spark Plugs.- Sensors.- Environmental Problems.- 7 Engine Accessories.- Speed Control.- Principles of Centrifugal Governor Action.- Spark Arresters.- Mufflers.- Air Cleaners.- Air Inlet Location.- Precleaners.- Dry-Type Air Cleaner.- Dust Composition.- Air Cleaner Tests.- Engine Cooling Systems.- Cooling Load.- Heat Transfer.- Air Cooling.- Radiator Design.- Radiator Construction.- Temperature Control.- Antifreeze Materials and Coolants.- Corrosion and Radiator Deposits.- Pressure Cooling.- Quantity of Air.- Fans.- Engine Cooling Summary.- 8 Lubrication.- Types of Lubricants.- Properties of Lubricants.- Viscosity.- Classification of Oil by Viscosity.- Classification by Service.- Universal Tractor Oils.- Oil Additives.- Journal Bearing Design.- Oil Contamination.- Oil Filters.- Lubricating Oil Systems.- 9 Human Factors in Tractor Design.- Operator Exposure to Environmental Factors.- Operator Exposure to Noise.- Operator Exposure to Vibration.- The Operator-Machine Interface.- Noise and Vibration Control.- Operator Seating.- Sound Control in Operator Enclosures.- Spatial, Visual, and Control Requirements of the Operator.- Rollover Protection for Wheeled Agricultural Tractors.- Thermal Comfort in Operator Enclosures.- Safety.- 10 Traction.- Traction Mechanics.- Mohr-Coulomb Failure Criteria.- Traction Performance Equations.- Traction Prediction from Dimensional Analysis.- Performance of Four-Wheel, Tandem, and Dual Tires.- Tire Size, Load, and Air Pressure Relationship.- Radial-Ply Construction.- Tread Design.- Effect of Lug Spacing.- Traction Improvement.- Tracks.- Tire Testing.- Traction Devices for Paddy Fields.- 11 Mechanics of the Tractor Chassis.- Simplifying Assumptions.- Equations of Motion.- Static Equilibrium Analysis-Force Analysis.- Static Equilibrium Analysis-Maximum Achievable Drawbar Pull.- Static Equilibrium Analysis-Four-Wheel-Drive.- Longitudinal Stability.- The Tractor as a 2-Degree-of-Freedom Vibratory System.- Transient and Steady-State Handling.- Lateral Stability in a Steady-State Turn.- Three-Dimensional Static Analysis.- Center of Gravity Determination.- Moment of Inertia Determination.- 12 Hydraulic Systems and Controls.- Hydraulic Component Symbols.- Hydraulic Components.- Motor Performance.- Accumulators.- Valves.- Hydraulic Fluids.- Classification of Hydraulic Controls.- Draft Sensing.- Automatic Control.- Complete Hydraulic System.- Power Steering.- Noise in Hydraulic Systems.- Hitches.- Tractor Kinetic Energy.- Integral Hitch Systems.- Three-Point Hitches.- Quick-Attaching Coupler for Three-Point Hitches.- 13 Transmissions and Drive Trains.- Complete Drive Train.- Transmission Types.- Friction Brakes and Clutches.- Spur and Helical Gears.- Bevel Gears.- Gear Design.- Planetary Gear Systems.- Differentials.- Transmission Drive Shafts.- Antifriction Bearings.- Drive Train Speeds and Loads.- Electronic Transmission Controls.- Torsional Vibration.- Computer Simulation.- 14 Tractor Tests and Performance.- Tractor Performance Criteria.- Power Measurement Methods.- Absorption Dynamometers.- Electric Direct Current Dynamometers.- Shop-Type Dynamometers.- Drawbar Dynamometers.- Torsion Dynamometers.- Chassis Dynamometer.- Power Estimating-Field Method.- Air-Supply Measurement.- Engine Pressure Indicators.- Fuel Flow Meter.- The Nebraska Tractor Tests.- Globalization of the Tractor Industry.- Correction for Atmospheric Conditions.- Torque Curves.- Engine Performance.- Efficiency of Tractor Engines.- Actual Power Output and Fuel Consumption.- Tractor Reliability.- Appendixes.- A Standards for Agricultural Tractors.- B Standard Graphical Symbols.- C Agricultural Tractor Tire Loadings, Torque Factors, and Inflation Pressures-SAE J709d.- D Conversion Factors.