I am writing you because I would like to clarify a doubt regarding the mathematical model to simulate Variable Valve Actuation or the so called VVA.
I raise that question because I have read lot of information specially about VVA in several books as Heywood (1989), Stone (1999), Giacosa (1970), Benson (1979), Genasan (2013), Pucher (2010), Winterbone (2000) and in many SAE papers. Actually, I have been using the parabolic method developed by Sherman & Blumberg and applied in Gallo (1990), Velasquez (1992) and BECERRA (1996). The tests I have done show that the parabolic method, the sine function model (by Genasan) and the theoretical valve lift with a fourier serie SILVA (2004) cannot achieve good agreements under early intake valve closure and late intake valve closes or when the valve keeps on opening for a long period.
I would like to use mathematical equations for VVA model together with Zero-dimensional model to simulate Diesel Engine process with double Wiebe function and Flow through a restriction (Heywood). This would be the following: Discharge coefficient in intake/exhaust valve, effective flow area, valve geometry. I have chosen the methodology proposed by KASTNER (1964) and TAYLOR (1985) to do so.
I would be very thankful if you could give me any help or any kind of information or piece of advice.
I don't think there is a special approach for VVA valve lift. 0D models are especially nice to play around with valve timing. To estimate the effective valve lift area I used the formulas derived in Ximing Dong: Zur Berechnung des geometrischen Öffnungsquerschnitts von Kegelventilen. MTZ 46 (1985).
What does it mean that your results were wrong? The mass flow through the valves? In LIVC you may have some troubles estimating the discharge coefficient for the backflow.
You may use good 1D Flow codes for the flow thru engine cycle. It will help to solve all your calculations related to VVT/VVA
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