Piston

Inside diameter of the piston cylinder wall. The Piston block uses this measurement to compute the torque table. You must specify a value greater than zero.

Distance from the fully retracted position to the fully extended position of the piston. The Piston block uses this measurement to convert pressure on the piston into torque values. You must specify a value greater than zero.

Distance from the center of the piston pin hole to the center of the crankshaft hole in the piston rod. The block uses this measurement to convert pressure on the piston into torque. You must specify a value greater than zero.

Number of piston phases required to intake, compress, combust, and exhaust the combustion gases. Typically, engines are two-stroke or four-stroke. You must use a multiple of two.

Parameter group that you want the block to use to parameterize the pressure data.

Angle of the piston crank starting at or above the minimum angle and ending at or below the maximum angle. You can calculate the minimum or maximum angle by multiplying the number of strokes by -90 degrees or 90 degrees, respectively. You must specify at least two values.

Each element in Crank angle vector corresponds to an element in Pressure vector (gauge) or the M-row of Pressure matrix (gauge) or each Pressure 3D matrix (gauge) matrix.

Different throttle positions that correspond to the pressures in the Pressure matrix (gauge) or Pressure 3D matrix (gauge) parameters. The throttle position must remain in the range [0,1] with 0 representing no throttle and 1 representing full throttle.

Each element in Throttle vector corresponds to the N-column of Pressure matrix (gauge) or each Pressure 3D matrix (gauge) matrix.

Dependencies

To enable this parameter, set Pressure parameterization to By crank angle and throttle or By crank angle, throttle, and crank velocity.

Different crank velocities that correspond to pressures in Pressure 3D matrix (gauge).

Each element in Crank velocity vector corresponds to one of the O-matrices of Pressure 3D matrix (gauge).

Dependencies

To enable this parameter, set Pressure parameterization to By crank angle, throttle, and crank velocity.

Vector of pressure values that correspond to different crank angle positions.

Dependencies

To enable this parameter, set Pressure parameterization to By crank angle.

Matrix of pressure values that correspond to different crank angle and throttle combinations. The default value is [0, 0, 0, 0; 0, .9, 2.4, 3; 0, 6, 16, 20; 0, 15, 40, 50; 0, 6, 16, 20; 0, 3, 8, 10; 0, 2.4, 6.4, 8; 0, 0, 0, 0] bar.

The elements of Crank angle vector correspond to the M-rows in Pressure matrix (gauge). The elements of Throttle vector correspond to the N-columns in Pressure matrix (gauge).

Dependencies

To enable this parameter, set Pressure parameterization to By crank angle and throttle.

Concatenated matrix of pressure values that correspond to the various crank angle, throttle, and crank velocity combinations. The default value is cat(3, [0, 0, 0, 0; 0, .9, 2.4, 3; 0, 6, 16, 20; 0, 15, 40, 50; 0, 6, 16, 20; 0, 3, 8, 10; 0, 2.4, 6.4, 8; 0, 0, 0, 0], [0, 0, 0, 0; 0, .9, 2.4, 3; 0, 6, 16, 20; 0, 15, 40, 50; 0, 6, 16, 20; 0, 3, 8, 10; 0, 2.4, 6.4, 8; 0, 0, 0, 0], [0, 0, 0, 0; 0, .9, 2.4, 3; 0, 6, 16, 20; 0, 15, 40, 50; 0, 6, 16, 20; 0, 3, 8, 10; 0, 2.4, 6.4, 8; 0, 0, 0, 0]) bar.

The elements of Crank angle vector correspond to the M-rows. The elements of Throttle vector correspond to the N-columns. The elements of Crank velocity vector correspond to the matrices you concatenate along dimension O.

By default, M = 8, N = 4, and O = 3.

Dependencies

To enable this parameter, set Pressure parameterization to By crank angle, throttle, and crank velocity.

Aggregate viscous friction coefficient of the main and rod bearings. The block uses this parameter to compute the viscous power losses between the base and follower shafts.

Point in the engine cycle when the piston reaches top dead center. The engine cycle spans in angle from -S*180 to +S*180 degrees, where S is the value of the Number of strokes per cycle parameter.

Crank angle at time zero relative to a top dead center position.

Model for calculating fuel consumption. Model parameterizations are compatible with standard industrial data.

Selecting any option other than No fuel consumption enables the FC port and related parameters. When you set Fuel consumption model to No fuel consumption, the block does not calculate fuel consumption. Selecting this option increases simulation speed.

Volume of fuel consumed in one crankshaft revolution.

Dependencies

To enable this parameter, set Fuel consumption model to Constant per revolution.

Vector of engine speeds used in lookup table parameterizations. The vector length must match the Torque vector.

Dependencies

To enable this parameter, set Fuel consumption model to one of these settings:

Vector of engine torques used in the lookup table parameterizations. The vector length must match the Speed vector parameter.

Dependencies

To enable this parameter, set Fuel consumption model to Fuel consumption by speed and torque or Brake specific fuel consumption by speed and torque.

Matrix of fuel consumption rates corresponding to engine speed and torque vectors. The number of rows, P, must equal the number of elements in the Speed vector parameter. The number of columns, Q, must equal the number of elements in the Torque vector parameter. The default value is [.5, .9, 1.4, 1.6, 1.9, 2.7, 3.4, 4.4; 1, 1.7, 2.7, 3.1, 3.6, 5, 6, 7.4; 1.4, 2.7, 4, 4.8, 5.6, 7.5, 8.5, 10.5; 2, 3.6, 5.8, 6.7, 8, 10.4, 11.7, 13.3; 2.5, 4.8, 7.9, 9.4, 10.8, 14, 16.2, 18.6; 3.1, 6, 10.3, 11.9, 13.8, 18.4, 22, 26.5] g/s.

Dependencies

To enable this parameter, set Fuel consumption model to Fuel consumption by speed and torque or Brake specific fuel consumption by speed and torque.

Vector of brake mean effective pressure (BMEP) values. The BMEP satisfies the expression:

where:

Dependencies

To enable this parameter, set Fuel consumption model to Fuel consumption by speed and torque or Brake specific fuel consumption by speed and brake mean effective pressure.

Matrix of brake specific fuel consumption (BSFC) rates. BSFC is the ratio of the fuel consumption rate to the output power. The number of rows, P, must equal the number of elements in the Speed vector parameter. The number of columns, Q, must equal the number of elements in the Torque vector parameter. The default value is [410, 380, 300, 280, 270, 290, 320, 380; 410, 370, 290, 270, 260, 270, 285, 320; 415, 380, 290, 275, 265, 270, 270, 300; 420, 390, 310, 290, 285, 280, 280, 285; 430, 410, 340, 320, 310, 300, 310, 320; 450, 430, 370, 340, 330, 330, 350, 380] g/hr/kW.

When you set Fuel consumption model to Brake specific fuel consumption by speed and torque, enter a matrix with BSFC rates corresponding to engine speed and torque vectors.

When you set Fuel consumption model to Brake specific fuel consumption by speed and brake mean effective pressure, enter a matrix with BSFC rates corresponding to engine speed and brake mean effective pressure (BMEP) vectors.the number of rows must equal the number of elements in the Speed vector parameter. The number of columns must equal the number of elements in the Brake mean effective pressure vector parameter.

Dependencies

To enable this parameter, set Fuel consumption model to Brake specific fuel consumption by speed and torque or Brake specific fuel consumption by speed and brake mean effective pressure.

Interpolation method to calculate fuel consumption at intermediate speed and torque values. Outside the data range, fuel consumption remains constant at the last value given in the lookup table for both methods.

Dependencies

To enable this parameter, set Fuel consumption model to one of these settings: