Introduction toSTELLA
Structural Thinking Experiential LearningLaboratory with Animation
Commerical ProductsGraphical Interface Differential Equation Solvers (GIDES)
PStella< Free run-time version
PBerkeley Madonna< Free run-time version< Solves “stiff” differential equations
PVisSim (Mathcad)PSimulink (Matlab)PSimilePModel Maker
Stella InterfaceStella “Layers” – Modeling
PConstructModel usingBuilding Blocks,Tools, Objects
POutputs
Layer Navigation
Map/Model ToggleChange to P2 (or else!)
Run Controller
Stella InterfaceStella “Layers” – Mapping
PTextPOutput Tables
and GraphsP Input using
Slides andDials
PPicturesPQuick Time
Movies
Stella InterfaceStella “Layers” – Equation
P Initial Values ofStocks
PConnectorInformation
PDifferentialEquationsRepresentingthe TimeDependence ofStocks
Stella InterfaceMenu / Icons
Stella InterfaceBuilding Blocks – Stocks
Value Undergoing a Change
Stella InterfaceBuilding Blocks – Flow
Change of Stock with Respect to Time
Stella InterfaceBuilding Blocks – Converter
ConstantsTransformation Equations
Stella InterfaceBuilding Blocks – Connectors
Links Building Blocks
Stella InterfaceTools – Hand
General Purpose Editing ToolCursor Pointer
Stella InterfaceTools – Dynamite
Delete (No “Undo”)
Stella InterfaceObjects – Graph Pad
Graphing Results
Stella InterfaceObjects – Table Pad
Spreadsheet-like Table of Results
Solving of Differential EquationsTaylor Series
Solving of Differential EquationsEuler Method
First 2 terms
Solving of Differential EquationsRunge-Kutta 2
First 3 Terms
Solving of Differential EquationsRunge-Kutta 4
First 5 Terms
Simple Model – Falling CalculatorSystem
y = heightyN = velocity = (acceleration)(time)yO = acceleration = g = 9.8 m s-2
Simple Model – Falling CalculatorStella Model
Simple Model – Falling CalculatorStella Model – Equation Layer
dCdt
kC
C Ckt
o
= −
= +
2
1 1
Simple Model – Falling CalculatorStella Model – Accuracy
PAir FrictionPBounce
Chemical KineticsSure looked like a natural fit to me!!
Kinetics ModelDimerization of Cyclopentadiene2nd Order Diels-Alder Reaction
2
Kinetics Model
Michaelis-MentonLen Soltzberg (Simmons College)
E + S º (ES)
(ES) 6 P + E
Oscillating ReactionsCriteria
PTwo or more coupled reactionsPAutocatalytic
Oscillating ReactionsBriggs-Rauscher
PH2O2
PKIO3 and H2SO4
PHOOCCH2COOH, MnSO4, starch
~15 s for each cycle
Oscillating ReactionsBelousov-Zhabotinskii
P 18 reversible stepsP 21 different chemical species
BrO3- + HBrO2 + H3O+ 6 2 BrO2 + 2 H2O
2 BrO2 + 2 Ce3+ + 2 H3O+ 6 2 HBrO2 + 2 Ce4+ + 2 H2O
A + Y 6 X + PX + Y 6 2PA + X 6 2X + 2Z2X 6 A + PB + Z 6 (f/2) Y
whereA = BrO3
-
X = HBrO2Z = Ce4+
P = HOBrB = organicY = Br -
Oregonator by Len Soltzberg (Simmons College)
Other ApplicationsRod Schluter (Formerly of CofC)
Acid/Base Equilibrium
H+ + OH- 6 H2O
D Tu
xe
dxD x( / )θ =−∫
313
3
( )
( )[ ]
U U RTD
C R Du
e
S R D e
A U RT e D
v u
u
u
− =
= −−
⎛⎝⎜
⎞⎠⎟
= − −⎡⎣⎢
⎤⎦⎥
− = − −
−
−
0
0
3
3 4 31
343
1
3 1
ln
ln
Other ApplicationsDebye Theory for Monatomic Crystals
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