Climate zones in the testing facility

Reproducible measurements obtained under extreme climate conditions are becoming increasingly important in drive development for both conventional and purely battery-powered cars. A new method from IAV makes it possible to transform almost any IAV test unit, from traditional engine test benches to those for batteries, into a full climate testing unit at low cost and with minimal mechanical effort.

IAV Klimabox 02

Low outdoor temperatures and high humidity encourage the formation of deposits on components and can damage the engine when exhaust gas is recirculated in combustion engines. To investigate the effects of these kinds of environmental climate conditions, vehicle manufacturers typically use special testing facilities. But time slots are often hard to come by and very expensive, while test drives in road traffic are of limited utility when it comes to taking the relevant measurements.

The “variable IAV climate box” can be used to do things like set the temperature and humidity as control parameters for component tests involving engine test benches. This will unlock a greater depth of testing using conventional IAV test units in the future, supplying additional information for development and validation.

The IAV climate box measures 3000 x 3000 x 2500 mm. It is installed on an IAV test unit around the relevant test subject, such as a combustion engine, and conditioned using mobile cooling and climate control assemblies. This retrofit “climate test unit” is also integrated into the existing test unit automation. The IAV climate box (10 kW of cooling performance at minus 20 °C) has a performance range extending over temperatures from minus 20 °C to 15 °C and humidity from 10% to 90%.

“We wanted to generate a mobile application that lets us take a box like this from test unit A to test unit B,” explains Jörg Jacob, team manager of Powertrain System Development at IAV.

«This variable solution can be used in endurance runs or mechanical testing, for example, or it can be used in functional testing – whatever the customer wants to do.»

Jörg Jacob — Team manager of Powertrain System Development at IAV

Also usable for electrical components

There is an ever-growing range of development topics relating to electronic powertrains, which is also driving increasing demand for test capacity in the electric mobility segment. The IAV climate box can be used here as well, says Ronny Mehnert, team manager of Energy & Thermal Management at IAV.

Batteries are also prone to condensation, because moist air enters the system through the ventilation unit’s semipermeable membrane. As temperatures fluctuate, the condensate forms droplets and collects in the battery, for example when the drying unit storage capacity is exceeded. Alongside high-voltage batteries, fuel cells, power electronics, and inverters are all components that are sensitive to condensation.

“The variability this box allows is not limited to just combustion engines,” Jacob says. “It can be used in various ways, including for electric car and battery test units where small, low-cost housings are needed.”

The design has proven its effectiveness through extensive tests and simulations involving deposition and condensation. The virtual analyses also offer insight into increases and decreases in the amount of condensate in relation to ambient humidity. 3D calculations have also been used to identify where the water arises and how it is transported in the cooler and pipe system, and thanks to modern topology, optimization and remedial actions have been developed, for example by evenly distributing the flow within the cooler or water separator.

One thing is clear: Test facilities are critically important to quality assurance in the automotive industry. The more functional and flexible they are, the greater the competitive advantages they can yield. Thus far, IAV has used the climate box exclusively in customer projects with OEMs and suppliers at in-house locations, but the company is also considering a solution on a product basis.

IAV Klimabox 01

IAV’s climate box – quickly transforming an engine test Bench into a climate Cell

  • Use any test bench for assemblies as a conditioned test bench
  • Short assembly time
  • Different virtual vehicles as well as route and driving profiles
  • No restrictions on the use of exhaust gas measurement
  • Proven high comparability of results with a climate test bench
Climate Box Features
  • Insulated floor
  • Access through one door
  • Visual surveillance with camera system
  • Actual values and fault messages are monitored in the test bench automation system
Operating options
  • Dynamic cycles (e.g., WLTC +20 °C / -7 °C or Shanghai cycle +35 °C, 90-95% humidity possible)
  • Standard endurance test bench can be retrofitted with a mobile climate box (e.g., no need to change test bench for operating conditions close to the dew point)
  • Conditioning of cooling water/oil circulation
  • Conditioning of intake air
  • Moisture regulation (stable) up to 95% humidity from 10 °C