KULI offers a powerful programming interface to execute and control simulations from external tools.
The attached examples demontrate the usage of this programming interface with different scripting and programming languages (Python, Matlab, C++, C#/.NET).
Keywords: automation, script, COM, Python, C++, 36 KB
This example shows how a VTM control system can be implemented using a state machine. There is no cooling system or A/C system modeled explicitly, but instead both the evaporator and the PTC heater in the HVAC box are represented by area resistances with heat sources. The HVAC blower is modeled as an air mass flow source. The focus is put on the control subsystem, which automatically engages cooling or heating modes according to cabin temperature levels and controls heater, evaporator, fan and HVAC flaps so that a target temperature is reached in a specific cabin zone. This subsystem is made mostly generic and with simple interfaces to allow easy re-use in a wide range of applications. Additionally the cabin model shows an application of the “variable flow fields” feature to correctly reproduce different conditions during heating (air goes to legroom) and cooling (air goes to passenger vents).
Keywords: VTM, VCU, control, state machine, HVAC, comfort, cabinUsable from release: KULI 13
This model is an approximate representation of the Mitsubishi i-MiEV including battery, E-Drive, HVAC-System and controls, cabin model and driving simulation. It is intended as a showcase on how to model certain parts of an electric vehicle and as a base for user models.
The battery is an air cooled battery, which, during fast charging, is cooled with cold air from the HVAC box. HVAC controls are modeled by a state machine in combination with several P controllers. Driving simulation is a simple longitudinal simulation intended for transient prediction of motor operating points. The simulation model is capable of predicting cabin temperatures and the related vehicle energy consumption and range for different ambient conditions (summer, winter…) and any user-defined drive cycle.
Keywords: vehicle model, VTM, i-MiEV, Mitsubishi, workshop, complete, range
Usable from release: KULI 14.1
KULI hvac is an efficient tool to simulate air conditioning (A/C) systems. On the other hand, KULI base allows to calculate refrigerant properties. By default, media data of several widely-used refrigerants are distributed with KULI. However, custom-tailored applications can require additional ones which have not been provided. This manual describes how to set up a new refrigerant media file for KULI using the third-party software ©REFPROP by NIST.
In the course of electrification, A/C systems get increasingly complex fulfilling new tasks. With the help of KULI hvac, dependencies and interactions between engine compartment flow, engine cooling system and A/C in the vehicle interior can be calculated. KULI base allows requirements-driven pre-selection of refrigerants based on calculation of key properties at given ambient conditions.
Due to the described recent developments, there is a strong need for non-standard refrigerants or mixtures to be incorporated into KULI as custom-tailored media files. This manual describes in detail how to do so. First it gives general information about the KULI Refrigerant Media File explaining its structure and its content. Next it provides an overview on how to generate the input data for the file. Step-by-step instructions guide the user through the setup using ©REFPROP by NIST. Multiple screenshots illustrate how to select the substance, the reference state, the units and the data ranges in the pressure-enthalpy diagram. Further informative figures display selection of properties, change of property order, calculation of values, and copying of data into the KULI Media File. The latter steps need to be done for the Wet Steam and Vapor/Fluid Areas separately. Helpful tips complement the manual preventing common mistakes and representing the experience of the KULI development team. Last but not least, the KULI Media File needs to be verified; this can be done by KULI MediaX.
Keywords: reference data, Mollier chart, Mollier diagram, heat pump, phase change, evaporator, evaporate, condenser, condensateUsable from release: KULI 8.0-1.04
The dynamic solver considers fluid transport, convection and heat conduction within a fluid. To this end, every component inside the circuit carries a fluid volume. This approach enables transient thermal simulation of small and even zero mass flows. As the exemplary driving simulation shows, warm-up, cooling-down and converging of resting and low velocity fluids will be calculated precisely.
The example simulates cooling of an engine loaded by three, successive NEDC driving cycles demonstrating the beauty of transient simulations using KULI´s dynamic solver. The engine is lubricated and cooled by a closed oil circuit which is put into contact with a water/glycol circuit after a first warm-up. It considers the thermal inertia and thermal conductivity of fluid volume held by the components. Heat sources in the oil and the water/glycol circuit, respectively, model the rejected heat. Dummy tubes account for the fluid volumes held by the piping system of the engine.
A thermostat controls the coupling of the oil circuit with the water/glycol circuit via a parallel flow cooler. When its temperature is above 80 °C, it will open a confluence and heat will be exchanged. A second thermostat in the water/glycol circuit controls the coolant flow through the radiator. It keeps the respective branch shut until it reaches a temperature of about 90 °C. Then it begins to open which causes the high velocity, warm coolant in the bypass branch to be mixed with the resting, cold one from the radiator and its supply/discharge pipes. As a consequence the engine will experience a cold flush of coolant. The dynamic solver allows to simulate this phenomenon, calculating the transient thermofluidic properties of converging fluids of different temperatures and velocities. In addition to the already described components, the water/glycol circuit comprises further tubes, fluid resistances, a coolant pump and a heater. Featuring these components, the water/glycol circuit is modeled in a more detailed way than the oil circuit in contact with it.
Keywords: cold sip, temporal, time-critical, thermal mass, advection, point massUsable from release: KULI 13
This example demonstrates how to use KuliCompInterface in Matlab to create a KULI radiator file.
As a prerequisite, KuliCompInterface version 13 must be available on the system.
The data used in the sample is almost similar to the ex_offroad.kuliRAD. As a result the written radiator file is similar to ex_offroad.kuliRAD. Pressure drop and heat data are read from the corresponding .csv files. All other data are hard-coded in the .m file.
Due to the fact, that KuliCompInterface is only available as 32-bit, also Matlab has to be 32-bit.
Keywords: KuliCompInterface, MatlabUsable from release: KULI 12
In some transient application it is required to run a certain cycle (e.g. an NEDC) several times. It would be desirable to specify the boundary conditions of the cycle just once and then obtain this data repeatedly. The modulo function of the user defined calculation controller can be used to accomplish this task very easily.
This example is based on the default example ExEngine_HYBRID_adv and shows how the user defined calculation object is used to take the time, then use the modulo function to compute the remainder when dividing by the cycle length and finally define the simulation parameters with the help of maps.
Keywords: simulation parameter repeat cycle boundary conditions
Usable from release: KULI 12
These examples show how to set up a component test rig for a cross flow heat exchanger in KULI with the possibility to accurately specify the boundary conditions.
In order to predict the performance of a given cross flow heat exchanger (e.g. a radiator), it is sometimes quite useful to model a component test rig in KULI. This is particularly useful if a user receives measurement data or a KULI file of a component and wants to observe how this component performs at certain boundary conditions. In order to accurately specify all inlet conditions (temperatures, flow rates, pressures, humidity) at the same time, different modeling is required depending on the way how the air flow rate is defined (mass flow or entry volume flow or entry speed). The models in this example demonstrate how this can be achieved. They can be used as templates for test rigs in KULI. The component itself and the boundary conditions can easily be exchanged.Usable from release: KULI 12
In modern cooling system applications sometimes a radiator (coolant-air heat exchanger) is used to cool-down air (instead of air cooling-down the coolant). This makes it necessary for the model to consider potential condensation effects in the air.
Specifically only a part of the cooling power of the coolant is sensible heat on the air-side, while the rest compensates the heat from the phase change of the condensing air humidity (latent heat). Accordingly also a condensate mass flow is calculated.
As the KULI radiator component does not have native support for these effects, this library example provides additional functionality using calculation controllers and two air-side heat sources / sinks.Usable from release: KULI 12
This Excel sheet can directly be used to generate the data for a single pass of a 2 layer Cross-Counter-Flow Cooler (radiator, charge air cooler or oil cooler).
In special cases a cooler consists of two layers behind each other. In KULI this can be modeled as two separate coolers connected in series. As usually pressure drop and thermal performance data are available for the whole component only, the target is to generate the data for a single pass of the heat exchanger. This package provides Excel sheets and KULI files to perform this task. The Excel sheets require the Excel Add-In “Solver” and “KuliAnalysis2”. A detailed workflow description is given as well.Usable from release: KULI 12