The mean piston speed
[[bar.S.sub.p]], m/s, defined as:
In this regime it can be demonstrated that the turbulence level directly scales with engine speed, or more specifically with piston speed
. One way in which turbulence can be enhanced is by using the combination of intake port design and piston motion to generate large-scale tumble flow during the intake process, and recover the energy from the decaying tumble motion during compression as fine scale turbulence at the flame front .
This drives down power consumption, while the uniform piston speed
virtually eliminates pulsation in the flow of material, regardless of the pump's charge pressure.
With this squish area, the preferred mean piston speed
is less than 4,200 feet per minute.
Figure 7 shows the numerical and experimental flow patterns for LDPE and HDPE at piston speed
30 mm [min.sup.-1] through 2mm slit die.
The combination of a closed hood with a cooling air inlet together with a surprisingly low piston speed
of 3m/sec and optimised air flow over the cylinder keeps vibration levels to a minimum and the temperature of components to a very low level.
According to literature , assuming that the gas velocity is proportional to the average piston speed
Up, the heat transfer coefficient [K.sub.w] can be expressed with the following equation:
Optimization has shown that several kN's of reacting force can be reached for a shock-absorber having dimensions similar to conventional design at a piston speed
of 0.5 m/s.
A former editor of Car Craft and Hot Rod, and himself a racer, Baechtel sets out and explains calculations of such matters as engine displacement, compression ratio, torque and horsepower, intake and header size, injector sizing, and piston speed
. In many cases, measurement required is illustrated with photographs.
where [epsilon] is the compression ratio, w is piston speed
, S is the stroke of the piston, and y is the specific heat ratio.
Principal particulars of new Mitsubishi and Wartsila small-bore low-speed engines: Engine type RT-flex35 RT-flex40 RTA35/UEC35LSE RTA40/UEC40LSE Cylinder bore, mm: 350 400 Piston stroke, mm: 1,550 1,770 Power/cylinder, MCR, kW: 870 1,135 Speed range, rpm: 167-142 146-124 Brake mean effective 21.0 21.0 pressure, BMEP, bar: Mean piston speed
, m/s: 8.6 8.6 Number of cylinders: 5 to 8 5 to 8 Power range, kW: 3,475-6,960 4,550-9,080
A brushless servo digital drive provides a piston speed
range of up to 1200 mm/min.