Harrison, M. F.Rubio Unzueta P. L.De Soto, I.2005-11-222005-11-222004-12M. F. Harrison, I. De Soto and P. L. Rubio Unzueta, A linear acoustic model for multi-cylinder IC engine intake manifolds including the effects of the intake throttle, Journal of Sound and Vibration, Volume 278, Issues 4-5, 22 December 2004, Pages 975-1011.0022-460Xhttp://hdl.handle.net/1826/771http://dx.doi.org/10.1016/j.jsv.2003.12.009This paper presents a linear acoustic model of a multi-cylinder intake manifold that can be used as part of a hybrid time/frequency domain method to calculate the intake wave dynamics of practical naturally aspirated engines. The method allows the user to construct a model of almost any manifold of complex geometry. The model is constructed as an assemblage of sub-models: (i) A model for a straight pipe with both ends open and through-flow. (ii) A model for an expansion chamber consisting of three lengths of pipe laid end-to-end: a narrow bore pipe expanding into a wide bore pipe contracting into a narrower bore pipe once more. (iii) A model of a side-branch, which includes a model for a straight pipe with one end closed and a model for the three way junction that joins the side-branch to a length of flow pipe. (iv) A model for an expansion with two (or more) side-branches, which combines the sub-models (i, ii, iii) into a multi-way (n-way) junction model. (v) A model for an intake throttle. Good agreement with measurement has been found for each sub-model when bench-tested in isolation and encouraging agreement has been found when many sub-models are used together to model a complex intake manifold on a running engine.1886 bytes2547712 bytestext/plainapplication/msworden-UKArticle