Hi Sudeep,
I understand that you are seeking suggestions on simulating forced air convection for battery cells and packs, having already modelled natural convection and liquid cooling. It can be approached by using Simulink environment along with Simscape for physical modelling. While there is not a direct "forced air convection" block in the standard libraries, can achieve this by creatively using the available blocks and customizing them to simulate the effect of forced air cooling on the battery model. Here is how one can approach this:
1. Understanding Forced Air Convection:
Forced air convection involves moving cool air over the surface of the battery pack to remove heat. The rate of heat transfer due to convection can be calculated using the formula:
Where,
- (q) is the heat transfer rate (W),
- (h) is the convective heat transfer coefficient (W/m²K),
- (A) is the surface area of the battery exposed to air (m²),
- (Tsurface) is the surface temperature of the battery (K),
- (Tair) is the temperature of the air (K).
2. Using Convective Heat Transfer Block:
In Simscape, "Convective Heat Transfer" block can be used to model forced air convection. This block calculates heat transfer between a solid and fluid where the fluid temperature and flow rate are inputs to the block. To model forced air convection:
- Solid Interface: Connect this to thermal port of battery model where want to simulate heat removal.
- Fluid Interface: Simulate moving air by setting temperature of air and an effective heat transfer coefficient that accounts for forced air movement.
3. Determining the Convective Heat Transfer Coefficient:
The convective heat transfer coefficient ((h)) for forced air convection can vary significantly based on the speed of the air, the geometry of the battery pack, and other factors. It might require experimental data or literature review to find an appropriate value. Alternatively, computational fluid dynamics (CFD) simulations can provide detailed insights if precise modelling is necessary.
4. Simulating Air Flow:
- Temperature Input: Use a constant or variable source to set the air temperature based on the cooling system's specifications.
- Flow Rate: While "Convective Heat Transfer" block does not directly take flow rate as an input, adjust heat transfer coefficient ((h)) to reflect changes in the air flow rate. Higher flow rates typically increase the value of (h), enhancing the cooling effect.
5. Customizing Model:
For complex scenarios or to accurately capture behaviour of forced air convection cooling in battery packs, consider creating a custom block:
- Use MATLAB scripting capabilities to define a function that calculates heat transfer based on air flow rate, air temperature, and battery surface temperature.
- Incorporate this function into a Simscape block using Simscape language, which allows for creation of custom physical models.
6. Validation and Experimentation:
- Validate model against available experimental data. Adjust convective heat transfer coefficient and other parameters as needed to match observed behaviour.
- Experiment with different air temperatures and flow rates to optimize cooling strategy for specific application.
7. Integration with Thermal Management Systems:
Consider how forced air cooling integrates with overall thermal management system (TMS) of battery pack. This might involve simulating control strategies that adjust air flow in response to battery temperature or state of charge (SOC).
Hope it helps!
Best Regards,
Simar
