This presentation was made at the 2019 NAFEMS World Congress in Quebec Canada

Resource Abstract

The constant market pressure to put new recreational vehicles on the market with better performance and lower cost requires the use of advance engineering tools such as CFD.



BRP built a strong expertise in CFD modeling in the last 10 years and correlated CFD models with wind tunnel and field testing to ensure confidence in the models. The new BRP Can-Am RYKER on-road vehicle has pushed CFD a level up with extensive use of CFD modeling and experimental testing to minimize Cd.A, manage underhood heat, manage heat rejection to the rider, design engine peripherals and maximize rubber belt Continuously Variable Transmission (CVT) cooling. The use of those tools all along the development process led to a high level of readiness in the early prototype stages as well as allowing aero-thermal design validation in only 16 months and ensured product readiness prior to tooling release.



This paper cover:

• CFD influence in the design process

• Aerodynamic modeling: results and limitations.

• Aero-thermal calculations: potential and challenges.

• New application of CFD for CVT cooling prediction.



The article follow 3 steps:



CFD impact in the design process. Presentation of the progressive approach to the use of CFD in the design process. CFD impact in the early development phase to put a project on track and focus in the higher drag contributors, and the hot spot areas. This approach has led to the release of patents.



CFD in heat management. Presentation of a heat management model using 14 continuum (air, exhaust gas, cooling, solids, radiator exchange) to evaluate the heat transfer from the exhaust line, cooling system and engine bloc. CFD model was useful to predict rider thermal comfort and component surface temperatures.



CFD for CVT cooling prediction. CVT transmission using rubber belt generate lot of heat and their durability are directly linked to load and heat. This section will present the modelling of the transmission and internal cooling airflow to maximize belt durability. CVT test bench and field testing procedure are developed to validate the CFD model. A good correlation between flow prediction and sensitive parameters are now clearly identified.