Vehicle Dynamics & Powertrain Flashcards
7 cards from real CAE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Vehicle Dynamics & Powertrain flashcards as text
What is 'jounce' in suspension terminology?
Answer: The upward compression travel of the suspension from its static position
Jounce (also called compression or bump) is the suspension travel in the direction of wheel moving upward toward the body, compressing the spring.
In vehicle NVH engineering, what does 'structure-borne noise' refer to?
Answer: Vibrations transmitted through solid vehicle structures from excitation sources to the passenger compartment
Structure-borne noise propagates through solid connections (suspension, body mounts, chassis) from excitation sources such as the road surface or powertrain to the cabin.
How does a 'torque vectoring' system improve vehicle cornering performance compared to a conventional open differential?
Answer: It actively distributes more torque to the outer driven wheel to generate a yaw moment aiding rotation
Torque vectoring sends more torque to the faster-rotating outer wheel, creating a yaw moment that helps rotate the vehicle through the corner without relying solely on steering.
Which type of engine configuration inherently has better primary and secondary force balance in a four-cylinder arrangement?
Answer: Inline-four with a 180° firing order and two counter-rotating balance shafts
A balanced inline-four uses two counter-rotating Lanchester balance shafts spinning at twice engine speed to cancel the inherent secondary imbalance forces.
What is 'critical speed' in driveshaft design?
Answer: The rotational speed at which the driveshaft's natural resonant frequency causes whirling and vibration
Critical speed is the rotational speed matching the driveshaft's lateral bending natural frequency, causing whirling that can destroy the shaft if operated near it.
In a vehicle's steering system, what is 'returnability' and what primarily provides it?
Answer: The self-centering tendency of the steering after a turn, primarily provided by positive caster angle creating a restoring moment
Positive caster places the tire contact patch behind the steering axis projection, so vehicle forward motion creates a restoring moment that returns the wheel to straight ahead.
During chassis tuning, a 'push' complaint from a driver in a corner most likely indicates what suspension or tire condition?
Answer: Front tires are saturated and running at higher slip angles than the rear tires (understeer)
A 'push' or 'plowing' sensation means the front axle is understeering — the front tires have reached their lateral grip limit and the car wants to go straight instead of turning.