Sequential turbo surge line calculation?
Sequential turbo surge line calculation?
(OP)
Hello,
I am having trouble visualizing the compressor surge line in a sequential turbo application, both with equal size primary and secondary compressors as well as different sized compressors.
With equal size compressors I could plot them as two in parallel, but something tells me this is not correct. Wouldn't the boost provided by the primary compressor provide additional drive torque and shift the surge line left? How far left? Or is the separation of flow within the compressor the limiting factor?
With different size compressors I have no idea... help?
I am having trouble visualizing the compressor surge line in a sequential turbo application, both with equal size primary and secondary compressors as well as different sized compressors.
With equal size compressors I could plot them as two in parallel, but something tells me this is not correct. Wouldn't the boost provided by the primary compressor provide additional drive torque and shift the surge line left? How far left? Or is the separation of flow within the compressor the limiting factor?
With different size compressors I have no idea... help?





RE: Sequential turbo surge line calculation?
m_corr=m*(T1/T_ref)^0.5/(P1/P_ref).
T1 and P1 are the temperature and pressure at the compressor inlet, respectively. T_ref and P_ref are reference temperature and pressure standardized by the manufacturer. Garret has them as 298K and 1 bar (absolute), respectively. Other manufacturers may use different reference values, and some manufacturers display the X-axis of their maps in terms of a volume flow rate instead of mass flow (with a corresponding variation of the correction factor formula).
In a sequential setup, the second stage compressor inlet will see inlet air temperature and pressure above ambient, having being already compressed in the first stage. The correction above will correct your mass flows to plot the points on the map to the proper intersection of corrected mass flow and pressure ratio.
RE: Sequential turbo surge line calculation?
RE: Sequential turbo surge line calculation?
RE: Sequential turbo surge line calculation?
I am not clear on parallel sequential, especially with different sized compressors.
Thanks,
RE: Sequential turbo surge line calculation?