Introduction to Commercial and Off-Road Vehicle Cooling Airflow Systems

Vehicle functional requirements, emission regulations, and thermal limits all have a direct impact on the design of a powertrain cooling airflow system. Given the expected increase in emission-related heat rejection, suppliers and vehicle manufacturers must work together as partners in the design, selection, and packaging of cooling system components. An understanding and appreciation of airflow integration issues and vehicle-level trade-offs that effect system performance are important to the team effort. The severe duty cycles, minimal ram air, and sometimes unconventional package layouts present unique challenges.

The goal of this two-day seminar is to introduce engineers and managers to the basic principles of cooling airflow systems for commercial and off-road vehicles. Participants will learn about vehicle/product constraints, integration issues, cooling airflow, system resistance, fans, shrouds, radiators, coolers, estimating heat rejection, thermal accumulation, air recirculation, system performance, and underhood airflow. Basic concepts will be reinforced with in-class discussion of case studies.

Included in this seminar is the SAE paper A Systems Engineering Approach to Engine Cooling Design; The 44th L. Ray Buckendale Lecture.

Note: A similar course is available on demand!
PD331240ON - Introduction to Cooling Airflow Systems Web Seminar RePlay

What Will You Learn

By attending this seminar, you will be able to:
  • List fundamental factors and constraints of commercial and off-road vehicle cooling airflow systems
  • List vehicle requirements and system integration issues
  • Describe system resistance, fan, shroud, installation effects, and radiator characteristics
  • List fan/shroud aerodynamic design considerations and installation effects
  • Estimate heat rejection and thermal accumulation for system analysis
  • Analyze performance of diesel cooling airflow system
  • List alternatives for program management trade-off discussions on cooling airflow systems

Is This Course For You

OEM and supplier engineers and managers who are involved with vehicle cooling systems, or who interface with vehicle program management on these issues, will benefit from this seminar. Graduate-level students interested in cooling systems will also find it instructive.

Materials Provided

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Course Requirements

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  • Vehicle Overview
    • Cooling airflow system
    • A classification
    • Industrial air-cooled heat exchanger assemblies
    • System and sub-system requirements
    • Thermal recirculation
    • Challenges
  • Thermodynamics Review
    • First law
    • Radiator heat transfer equation
    • Bernoulli's equation
    • SCFM
  • Key Concepts
    • Thermal road map
    • Fan airflow map
    • Flow energy balance equation
  • Fan Airflow (and system airflow road map)
    • Fan classification
    • Specific speed
    • Fan characteristic curve and matching
    • Fan static pressure
    • Air performance test chamber (AMCA)
    • Pusher and puller fans
  • Fan Airflow (and system airflow road map) cont'd
    • Vehicle installation effects-fan position, tip clearance, obstructions, installed performarmance
    • Fan laws
    • System airflow road map
    • Basic principles of mechanical fan systems
  • Vehicle Airflow Restrictions-Energy Losses
    • Loss mechanisms-expansion and contraction loss, grilles, heat exchangers and underhood
    • Front-end and underhood flow patterns
    • Ram pressure recovery
    • Locating fan operating point
  • Compact Heat Exchangers (and system heat transfer equation)
    • Thermal classification
    • Compact heat exchangers
    • Calorimeters
    • Radiator effectiveness and pressure drop
    • Fouling considerations, air-side
    • Thermal accumulation
  • Estimating Powertrain Heat Rejection
    • Heat rejection to coolant -- Mean effective pressure; SAE dynamometer test procedures
    • Specific Heat Rejection (SHR) characteristic curve
    • Vehicle installation considerations
  • Diesel Cooling Airflow System - Case Studies and Exercises
  • Underhood Airflow
    • Thermal considerations, airflow pattern, and air temperature distribution
    • Flow visualization video (using water)