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CHEM-E3205 Bioprocess Optimization and Simulation Exercise 1 (13.9. 2016): Your task is to explore the Matlab Simulink program and the construction of simulation models. Start Matlab. Check out first Simulink software on-line manual (press F1 while you are in Matlab window) (SimulinkGetting Started Tutorials Create a Simple Model. After the demo, your task is to build a simple model for glucoamylase fermentation. This is a batch culture, in which Aspergillus niger fungus produces glucoamylase using glucose as a carbon source. Create a Simulink model and to examine its operations by setting the model parameter values and the initial state variable values. Run the model and make some tests with various parameter values and monitor the the model behavior. Here are the batch fermentation kinetic models which can be put in Simulink format: dX X dt dP YPS X dt dS 1 dX dt Y XS dt max S KS S YPS YPS ,max S KP S Simulink program can be found after the start-up of Matlab. Simulink program opens when you type the command “simulink” in Matlab command window or by clicking the Simulink icon. Simulink Library Browser window has icons, which opens different sub-libraries that contain the necessary components to build the model. We use a basic library called Simulink. Much of the blocks required can be found Commonly Used Blocks sub-library. The table below shows the other sub-libraries needed with their suitable blocks, as well as the related definitions, you may need to build the model. Sub-library Sources Block Constant Definitions (double click) giving the value of the constant Sinks Continuous Math Operations UserDefined Functions Signal Routing Scope Integrator Product Fcn Mux graphical monitoring of variables initial value for a variable number of inputs Definition of a function number of inputs Start by creating a new simulation window. On this screen you can pick up the blocks you need from the libraries (by dragging with the mouse from a library window or copying already existing blocks in the working window by holding down the Ctrl key same time). The blocks can be connected with the mouse from > sign in each block. The blocks and connecting lines may be named by double-clicking the icon name area below or directly the workspace. Each differential equation is presented in graphical form which describes state variable calculation and plot the simulation results eventually in Scope blocks. The equation calculations are defined in function blocks (Fcn), or in separate calculation blocks, such as e.g. Product-block for multiplication etc. See the example in Figure 1, wherein the specific growth rate is already modeled. Start with the construction of this model. Arrange the blocks from the left to the right for example: parameters (max, Ks) to Constant-blocks, then Mux (collects and indexes the incoming signals), then fcn (function, calculate then multiplied by biomass, then the dX/dt obtained is integrated and we have finally the value for biomass (state variable X). Once this first part of the model is complete, the simulation parameters can be set in the menu Simulation / Model Configuration Parameters (default settings most likely ok, eg. Start time = 0.0, Stop time = 10). Click the Scope block open and run your biomass simulating model. At this point, substrate concentration is still in a constant block, but now as you continue you change the block to an integrator block, which changes the substrate concentration from the given the initial value. Complete the model by adding blocks for substrate consumption and product formation and simulate the system using subtrate initial levels 10, 30 and 50 g/L and the inoculum concentration, ie. initial biomass levels of 0.1, 0.3, 0.5, and see the effect of final concentrations (and print the simulation results if you’re preparing a report). Concentrations of the initial values are placed into integrators (limits should be used for the substrate integrator so that concentration can not fall below zero). Figure 1. A part of the model: the specific growth rate model converted to a Simulink model Try first with these values: max : 1.5 (h-1) KS : 0.010 (g/l) YXS : 0.5 (g/g) YPS,max :0.006 (g/g) KP : 10 (g/l) X0: 0.30 g/l S0: 25 g/l P0: 0.01 g/l X S P max KS YPS YPS,max KP YXS biomass (g/L) glucose concentration (g/L) enzyme concentration (g/L) spesific growth rate (1/h) maximum spesific growth rate Monod constant (g/L) enzyme (product) yield coefficient (g/g) maximum yield coefficient (g/g) enzyme production constant (g/L) biomass yield coefficient (g/g)