How much does a C-Leg by otto bock cost?

Compare Brayton and Otto cycle?

The heat addition and rejection processes in otto cycle are of constant volume, whereas in brayton cycle, they are of constant pressure.

Why does the heat is added at constant volume in Otto cycle and at constant pressure in Diesel cycle?

in otto cycle the burning of fuel is instantaneously therefore a very small voulme is required for burning of fule

New invention in ic engine?

The latest in I.C.Engine design is FDCRT engine by me. After Otto, Diesel and Wankell this is the new design and this invention is a break through in i.C.Engine Technology.This is highly thermal efficient and have many advantages over the existing Reciprocating I.C.Engines. Patented in India For details Contact:- P.Radhakrishnan sprdesigns@yahoo.co.in Chennai - 600 083. Ph. 91-44-23700015. INDIA Mo: 99400 61515. .

What is the mechanical engineering syllabus for isro exam?

Mechanical Syllabus for ISRO Scientist Exam1. ENGINEERING MATHEMATICSLinear Algebra: Algebra of matrices, system of linear equations, eigenvalues and eigenvectors.Calculus: Taylor Series, Fourier Series, partial derivatives, total derivatives, definite and improper integrals, multiple integrals.Vector Calculus: Gradient, divergence and curl, line and surface integrals, Green, Gauss and Stokes' theorems.Differential Equations: Linear ODE's, first order non-linear ODE's, initial and boundary value problems, Laplace transform, PDE's-Laplace, wave and diffusion equations.Numerical Methods: Solution of system of linear equations, interpolation, numerical integration, Newton-Raphson method, Runge-Kutta method.Probability & Statistics: Gaussian, Weibul distribution and their properties, method of least squares, regression analysis, analysis of variance.2. APPLIED MECHANICS AND DESIGNEngineering Mechanics: Equivalent force systems, free-body concepts, equations of equilibrium, trusses and frames, virtual work and minimum potential energy. Kinematics and dynamics of particles and rigid bodies, impulse and momentum (linear and angular), energy methods, central force motion.Strength of Materials: Stress and strain, stress-strain relationship and elastic constants, Mohr's circle for plane stress and plane strain, shear force and bending moment diagrams, bending and shear stresses, deflection of beams torsion of circular shafts, thin and thick cylinders, Euler's theory of columns, strain energy methods, thermal stresses.Theory of Machines: Displacement, velocity and acceleration, analysis of plane mechanisms, dynamic analysis of slider-crank mechanism, planar cams and followers, gear tooth profiles, kinematics and design of gears, governors and flywheels, balancing of reciprocating and rotating masses.Vibrations: Free and forced vibration of single degree freedom systems, effect of damping, vibration isolation, resonance, critical speed of rotors.Design of Machine Elements: Design for static and dynamic loading, failure theories, fatigue strength; design of bolted, riveted and welded joints; design of shafts and keys; design of spur gears, rolling and sliding contact bearings; brakes and clutches; belt, ropes and chain drives.3. FLUID MECHANICS AND THERMAL SCIENCESFluid Mechanics: Fluid properties, fluid statics, manometry, buoyancy; Control-volume analysis of mass, momentum and energy, fluid acceleration; Differential equation of continuity and momentum; Bernoulli's equation; Viscous flow of incompressible fluids; Boundary layer, Elementary turbulent flow; Flow through pipes, head losses in pipes, bends etc.Heat-Transfer: Modes of heat transfer; One dimensional heat conduction, resistance concept, electrical analogy, unsteady heat conduction, fins; Dimensionless parameters in free and forced convective heat transfer, Various correlations for heat transfer in flow over flat plates and through pipes; Thermal boundary layer; effect of turbulence; Radiative heat transfer, black and grey surfaces, shape factors, network analysis; Heat exchanger performance, LMTD and NTU methods.Thermodynamics: Zeroth, First and Second laws of thermodynamics; Thermodynamic system and processes; Irreversibility and availability; Behaviour of ideal and real gases, Properties of pure substances, calculation of work and heat in ideal processes; Analysis of thermodynamic cycles related to energy conversion; Carnot, Rankine, Otto, Diesel, Brayton and Vapour compression cycles.Power Plant Engineering: Steam generators; Steam power cycles; Steam turbines; impulse and reaction principles, velocity diagrams, pressure and velocity compounding; Reheating and reheat factor; Condensers and feed heaters.I.C. Engines: Requirements and suitability of fuels in IC engines, fuel ratings, fuel-air mixture requirements; Normal combustion in SI and CI engines; Engine performance calculations.Refrigeration and air-conditioning: Refrigerant compressors, expansion devices, condensers and evaporators; Properties of moist air, psychrometric chart, basic psychometric processes.Turbomachinery: Components of gas turbines; Compression processes, Centrifugal and Axial flow compressors; Axial flow turbines, elementary theory; Hydraulic turbines; Euler-Turbine equation; Specific speed, Pelton-wheel, Francis and Kaplan turbines; Centrifugal pumps.4. MANUFACTURING AND INDUSTRIAL ENGINEERINGEngineering Materials: Structure and properties of engineering materials and their applications, heat treatment.Metal Casting: Casting processes (expendable and non-expendable) -pattern, moulds and cores, Heating and pouring, Solidification and cooling, Gating Design, Design considerations, defects.Forming Processes: Stress-strain diagrams for ductile and brittle material, Plastic deformation and yield criteria, Fundamentals of hot and cold working processes, Bulk metal forming processes (forging, rolling extrusion, drawing), Sheet metal working processes (punching, blanking, bending, deep drawing, coining, spinning, Load estimation using homogeneous deformation methods, Defects). Processing of Powder metals- Atomization, compaction, sintering, secondary and finishing operations. Forming and shaping of Plastics- Extrusion, Injection Molding.Joining Processes: Physics of welding, Fusion and non-fusion welding processes, brazing and soldering, Adhesive bonding, Design considerations in welding, Weld quality defects.Machining and Machine ToolOperations: Mechanics of machining, Single and multi-point cutting tools, Tool geometry and materials, Tool life and wear, cutting fluids, Machinability, Economics of machining, non-traditional machining processes.Metrology and Inspection: Limits, fits and tolerances, linear and angular measurements, comparators, gauge design, interferometry, Form and finish measurement, measurement of screw threads, Alignment and testing methods.Tool Engineering: Principles of work holding, Design of jigs and fixtures. Computer Integrated Manufacturing: Basic concepts of CAD, CAM and their integration tools.Manufacturing Analysis: Part-print analysis, tolerance analysis in manufacturing and assembly, time and cost analysis.Work-Study: Method study, work measurement time study, work sampling, job evaluation, merit rating.Production Planning and Control: Forecasting models, aggregate production planning, master scheduling, materials requirements planning.Inventory Control: Deterministic and probabilistic models, safety stock inventory control systems.Operations Research: Linear programming, simplex and duplex method, transportation, assignment, network flow models, simple queuing models, PERT and CPM.

Working of camless engine with electromechanical valve actuator?

INTRODUCTIONThe cam has been an integral part of the IC engine from its invention. The cam controls the "breathing channels" of the IC engines, that is, the valves through which the fuel air mixture (in SI engines) or air (in CI engines) is supplied and exhaust driven out. Besieged by demands for better fuel economy, more power, and less pollution, motor engineers around the world are pursuing a radical "camless" design that promises to deliver the internal - combustion engine's biggest efficiency improvement in years.Cams, lifters, pushrods... all these things have up until now been associated with the internal combustion engine. But the end is near or these lovely shiny metal objects that comprise the valve train hardware in your pride and joy. Camless engine technology is soon to be a reality for mass-produced vehicles. In the camless valvetrain, the valve motion is controlled directly by a valve actuator - there's no camshaft or connecting mechanisms. Various studies have shown that a camless valve train can eliminate many otherwise necessary engine design trade-offs. Automotive engines equipped with camless valve trains of the electro-hydraulic and electro-mechanical type have been studied for over twenty years, but production vehicles with such engines are still not available. The issues that have had to be addressed in the actuator design include:â€¢ Reliable valve performance costâ€¢ packagingâ€¢ power consumptionâ€¢ noise and vibrationNoise has been identified as the main problem with the electromechanical actuator technology, arising from high contact velocities of the actuator's moving parts. For this noise to be reduced, a so-called soft-landing of the valves has to be achieved.The valvetrain in a typical internal combustion engine comprises several moving components. Some are rotating and some are moving in a linear manner. Included are poppet valves that are operated by rocker arms or tappets, with valve springs used to return the valves to their seats. In such a system the parasitic power losses are major - power is wasted in accelerating and decelerating the components of the valvetrain. Friction of the camshaft, springs, cam belts, etc also robs us of precious power and worsens fuel economy, not to mention contributing to wear and tear. The power draw on the crankshaft to operate the conventional valve train is 5 to 10 percent of total power outputAnother factor working against the conventional valve train is that of the cam profile. Usually, it is fixed to deliver only one specific cam timing. The cam lobes have to be shaped such that when the valve travels up and down at the engines maximum speed it should still be able to slow down and gently contact the valve seat. The valves crashing down on their valve seats results in an engine that is real noisy and has a short life expectancy.Having different cam profiles will result in different engine characteristics. While high-rpm power and low rpm-torque can be each optimized, a compromise is required to obtain the best of both in the same engine. With Variable Valve Timing (VVT) technologies the compromise is getting better and better - reasonable low down torque and high-speed power are being produced by many sub 2-litre engines.But the problem remains that the cam grind is still a fixed quantity - or two fixed quantities in the case of Honda V-TEC engines. That's why the Electromechanical Valve Train is considered the next evolution of VVT. With the potential to dial in any conceivable valve timing at any point of the combustion cycle for each individual cylinder, valves can be opened with more lift and/or duration, as the computer deems necessary.Conventional valve train mechanismPushrod engines have been installed in cars since the dawn of the horseless carriage. A pushrod is exactly what its name implies. It is a rod that goes from the camshaft to the top of the cylinder head which push open the valves for the passage of fuel air mixture and exhaust gases. Each cylinder of a pushrod engine has one arm (rocker arm) that operates the valves to bring the fuel air mixture and another arm to control the valve that lets exhaust gas escape after the engine fires. There are several valve train arrangements for a pushrod.CrankshaftCrankshaft is the engine component from which the power is taken. It receives the power from the connecting rods in the designated sequence for onward transmission to the clutch and subsequently to the wheels. The crankshaft assembly includes the crankshaft and bearings, the flywheel, vibration damper, sprocket or gear to drive camshaft and oil seals at the front and rear.CamshaftThe camshaft provides a means of actuating the opening and controlling the period before closing, both for the inlet as well as the exhaust valves, it also provides a drive for the ignition distributor and the mechanical fuel pump.The camshaft consists of a number of cams at suitable angular positions for operating the valves at approximate timings relative to the piston movement and in the sequence according to the selected firing order. There are two lobes on the camshaft for each cylinder of the engine; one to operate the intake valve and the other to operate the exhaust valve.PROBLEMS RELATED TO CONVENTIONAL VALVE TRAINThe poppet valves that are operated by rocker arms or tappets, with valve springs used to return the valves to their seats. In such a system the parasitic power losses are major - power is wasted in accelerating and decelerating the components of the valve train. Friction of the camshaft, springs, cam belts, etc also robs us of precious power and worsens fuel economy, not to mention contributing to wear and tear. The power draw on the crankshaft to operate the conventional valve train is 5 to 10 percent of total power output.Another factor working against the conventional valve train is that of the cam profile. Usually , it is fixed to deliver only one specific cam timing. The cam lobes have to be shaped such that when the valve travels up and down at the engines maximum speed it should still be able to slow down and gently contact the valve seat.The single lobed cam is designed to operate the valves at only specific periods of the Otto cycle, thus preventing the engine from achieving maximum torque at higher rpms. The opening and closing of the valves is constrained by the geometry of the cam profile.ELECTROMECHANICAL CAMLESS VALVE ACTUATORIn recent years camless engine has caught much attention in the automotive industry. Camless valve train offers programmable valve motion control capability. An EMV system consists of two opposing electromagnets, an armature, two springs and an engine valve. The armature moves between the two magnets. When neither magnet is energized, the armature is held at the mid-point of the two magnets by the two springs located on either side of the armature. This system is used to control the motion of the engine valve. The engine valve is then in turn used to control the flow of air into and out of a combustion engine cylinder. The camless engine, where lift and valve timing can be adjusted freely from valve to valve and from cycle to cycle. It also allows multiple lift events per cycle and, indeed, no events per cycle-switching off the cylinder entirely.Computer controlled- opening and closing of valves make it possible to optimize the various phases of engine running. During idling phases, specific intake valve opening strategies make it possible to admit just the necessary quantity of air without having recourse to throttling the intake with a butterfly valve, something that generates consumption of fuel not used by the engine. Timing of valve opening or the latitude to only open a single intake valve make it possible to stabilize the engine on idling points which consume little fuel while ensuring a good level of drive ability or the driver.During urban driving and on the open road, both adequate opening and timing of the valves make it possible to admit a quantity of air limited to the requirement so the engine mixed with a massofburned gases purposely retained in the engine. This strategy ensures reduction of fuel consumption, polluting exhaust emissions, in particular, nitrogen oxides, produced by the engine. In terms of performance, the modularity of the system makes it possible to maximize the massof fresh air trapped in the cylinder at all engine speeds, ensuring both good torque and high power.Apart from these advantages, deactivation of the cylinder also delivers additional savings in terms offuel consumption and exhaust emissions when the engine is only using a small amount of its power as, or example, in urban use. In this mode, only halfof the cylinders are used to provide energy to the wheels, significantly limiting losses due to poor engine efficiency. The camless system is there or system which, on an air aspirated supercharged engine provides the customer with a significant improvement in engine features. In addition, it is a system that has a strong potential or evolution and its functions will be consumption required in order to implement combustion through auto-ignition, such as the HCCI system, which is under consideration as the next stage in the battle to reduce fuel consumption.Electromechanical Valve Train is considered the next evolution of VVT. With the potential to dial in any conceivable valve timing point of the combustion cycle for each individual cylinder, valves can be opened with more lift and/or duration, as the computer deems necessary. Just imagine that you have your latest 2-litre 16-valve EMVT powered engine on the dyno after installing an exhaust. Simply changing a couple of numbers on the computer will have a set of completely revised valve timing maps to suit your exhaust - or cold air intake for that mater. There will be no need for expensive cam changes that may not even give the results you are after. Electronically altering valve events will have a far more major impact on engine performance than any current electronically-controlled item.CONTROL DESIGNWhen the valve-closing event starts, the lower solenoid coil is deactivated, and the valve moves up towards its seating position by the mechanical spring force. An electro mechanical valve actuator works according to the spring-mass pendulum principle, which means that the system follows its own natural oscillation frequency, and external electromagnetic force is only needed for overcoming the friction loss. The electromagnetic actuator is only effective in a relatively short range closing to the seating position, and so it is not efficient in the sense of energy consumption to apply closed-loop control when the valve is still far away from theseating position. The system goes unstable as the engine valve moves to the region within one-third of the total lift.This type of system uses an armature attached to the valve stem. The outside casing contains a magnetic coil of some sort that can be used to either attract or repel the armature, hence opening or closing the valve.Most early systems employed solenoid and magnetic attraction/repulsion actuating principals using an iron or ferromagnetic armature. These types of armatures limited the performance of the actuator because they resulted in a variable air gap. As the air gap becomes larger (ie when the distance between the moving and stationary magnets or electromagnets increases), there is a reduction in the force. To maintain high forces on the armature as the size of the air gap increases, a higher current is employed in the coils of such devices. This increased current leads to higher energy losses in the system, not to mention non-linear behaviour that makes it difficult to obtain adequate performance. The result of this is that most such designs have high seating velocities (ie the valves slam open and shut hard!) and the system cannot vary the amount of valve lift.The electromechanical valve actuators of the latest poppet valve design eliminate the iron or ferromagnetic armature. Instead it is replaced with a current-carrying armature coil. A magnetic field is generated by a magnetic field generator and is directed across the fixed air gap. An armature having a current-carrying armature coil is exposed to the magnetic field in the air gap. When a current is passed through the armature coil and that current is perpendicular to the magnetic field, a force is exerted on the armature.When a current runs through the armature coil in either direction and perpendicular to the magnetic field, an electromagnetic vector force, known as a Lorentz force, is exerted on the armature coil. The force generated on the armature coil drives the armature coil linearly in the air gap in a direction parallel with the valve stem. Depending on the direction of the current supplied to the armature coil, the valve will be driven toward an open or closed position. These latest electromechanical valve actuators develop higher and better-controlled forces than those designs mentioned previously. These forces are constant along the distance of travel of the armature because the size of the air gap does not change.The key component of the Siemens-developed infinitely variable electromechanical valve train is an armature-position sensor. This sensor ensures the exact position of the armature is known to the ECU at all times and allows the magnetic coil current to be adjusted to obtain the desired valve motion.The ability of the electromechanical valve actuator to generate force in either direction and to vary the amount of force applied to the armature in either direction is an important advantage of this design. For instance, varying the value of the current through the armature coil and/or changing the intensity of the magnetic field can control the speed of opening and closing of the valve. This method can also be used to slow the valve closure member to reduce the seating velocity, thereby lessening wear as well as reducing the resulting noise.A special software algorithm is used to control the actuator coil currents such that the valves are decelerated to a speed near zero as they land - in conjunction with a switching time of barely three milliseconds. For the valves this means minimal wear and minimum noise generation. The 16-valve four cylinder engine that is currently undergoing tests in Germany, by Siemens, is equipped with 16 valve actuators and the corresponding armature-position sensors. A ECU is used and two cable rails connect the actuators to it. A 42-volt starter-generator provides the power.WORKINGCamless engines generally employ one of two types of camless actuators: electro-hydraulic or electro-mechanical valve actuators. The actuators receive input from the ECU via a dedicated CAN bus to open and close the poppet valves at a prescribed crankshaft angle timing, transition time and lift, matching the valve timing request sent by the ECU. Feedback is then sent by the actuators through the CAN bus to verify the actual occurrence of the operation.Electromechanical actuators are generally made with two solenoids and two springs. As can be seen in Figure 1 the ECM receives input from the crankshaft position sensor to close the valve, which activates Solenoid 1 by taking current from the battery. The current is passed through a pulse width modulator which tunes the amplitude of the current to control the speed of valve seating. The magnetic field created by Solenoid 1 attracts the armature in the upper position. Spring 1 is compressed and thus closes the valve. Solenoid 2 pulls the armature down to open the valve as shown in Figure 2.

How much does a C-Leg by otto bock cost?

Add your answer:

Compare Brayton and Otto cycle?

Why does the heat is added at constant volume in Otto cycle and at constant pressure in Diesel cycle?

New invention in ic engine?

What is the mechanical engineering syllabus for isro exam?

Working of camless engine with electromechanical valve actuator?

What is Otto Bock's population?

When was Otto Bock created?

How much does a C Leg by otto bock cost?

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Why you use cut-off ratio in diesel cycle not in Otto cycle?

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How much money does Otto Porter, Jr. make?

Where is artificial limbs make company in navi Mumbai please give you contact numper in USA internatinal company?

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