Using 1D simulations to optimize a supercharger for a twin charged DI gasoline engine

Transcription

1 Using D simulations to optimize a supercharger for a twin charged DI gasoline engine 5--6 Ragnar Burenius, Volvo car Group 5--6 USING D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

2 VEA architecture V8 SI6 I5P I5D NI4. GTDI Sigma.6 GTDI DWC. DV6C.6 VEA 5--6 USING D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

3 VEA differentiated by boosting T3 D T4 D3 T5 D4 T6 D USING D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP 3

4 Introduction T6 SC-turbo schematic 5--6 USING D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP 4

5 Engine Brake Torque [Nm] Supercharger Speed [rpm] Introduction - Operating range of the sc N/A Turbo Turbo+Supercharger Supercharger Speed Engine Speed [RPM] 5--6 USING D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP 5

6 Pressure ratio [-] INTRODUCTION SC Performance MAP,5,5.5,75,5.5 Steady state Transient,5 k 4k k k 3k 4k 5k 6k 8k k k 4k 6k 8k k Corrected massflow [kg/s],,4,6,8,,,4,6,8, Mass flow [kg/s] 5--6 USING D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP 6

7 Geometry Identification What looks like a complex shape is really just a helix extrusion 5--6 USING D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP 7

8 Geometry analysis in D A scheme for geometry definition of the meshing event was developed in Matlab 5--6 USING D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP 8

9 Segment Segment Segment 3 Segment 4 Segment 5 Segment 6 Segment 7 Segment 8 Segment 9 Segment Helix extrusion Areas of D integrated to volumes of 3D. Leakage lengths integrated to leakage areas. Discretized in ten segments to account for meshing and axial resolution USING D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP 9

10 Segment Segment Segment 3 Segment 4 Segment 5 Segment 6 Segment 7 Segment 8 Segment 9 Segment Implementation in D CFD The system of volumes and orifices is implemented as a model in GT-Power Outlet Inlet Rotor Rotor 5--6 USING D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

11 Pressure Ratio Pressure Ratio Results performance prediction.5.5 Measurement.5 D CFD Simulation k 4k k 4k k k 3k 4k 5k 6k 8k k k 4k 6k 8k k k k 3k 4k 5k 6k 8k k k 4k 6k 8k k k 4k k k 3k 4k 5k 6k 8k k k 4k 6k 8k k k k 3k 4k 5k 6k 8k k k 4k 6k 8k k k 4k Corrected massflow [kg/s] Corrected massflow [kg/s] Corrected massflow [kg/s] Corrected massflow [kg/s] Mass flow [kg/s].74 Mass flow [kg/s] USING D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

12 In-cycle analysis slow speed, PR= USING D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

13 Mass Flow [kg/s] Pressure In-cycle analysis High speed, PR=.5,5,5,75,5,5 3 4,,,9,8,7,6,5,4,3,, -, Pressure Volume Inlet flow Outlet flow Back flow Rotational angle [degrees] 5--6 USING D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP 3

14 The addition of Outlet slots 5--6 USING D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP 4

15 Mass Flow [kg/s] Mass Flow [kg/s] Pressure Pressure In-Cycle analysis Effect of outlet slots,5,5,75,5,5 Without outlet slots Without silencer slots 3 4 Rotational angle [degrees],5,5,75,5,5 With outlet slots With silencer slots,,,9,8,7,6 Pressure,5 Volume,4 Inlet flow,3 Outlet flow,, Back flow -, 3 4 Rotational angle [degrees],,,9,8,7,6,5,4,3,, -, Pressure Volume Inlet flow Outlet flow Back flow 5--6 USING D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP 5

16 Outlet slots Performance impact Simulation Test 3% 3 PR t-t PR t-t Corrected Corrected massflow massflow [kg/s] [kg/s] [kg/s]. Corrected Corrected massflow [kg/s].5. Corrected massflow [kg/s] massflow [kg/s] Corrected massflow [kg/s] [kg/s] Corrected 5--6 USING D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP 6

17 Conclusions Methodology presented for simulating a helix roots type blower using D CFD. Calculated performance compared to test data. Improvements in geometry implemented based on analysis of gas exchange model. Improvements verified in testing, and later put in production USING D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP 7