Update README.md

Author: ufechner7

README.md

@@ -31,23 +31,60 @@ pkg"test VortexStepMethod"
 ```
 
 ## Input
-- geometry, defined by section
+Three kinds of input data is needed:
+
+- The wing geometry, defined by section:
   - rec wing two section, two point + polars
   - kite: model of polars included, n sections to define
 
-- flow
+- The airflow:
   - v_app vector
 
-- config
-  - how many panels
-    -> two sections make a panel
+- The configuration:
+  - how many panels  
+    --> two sections make a panel.
+
+There is no input file yet, the input has to be defined in the code.
+
+### Example for defining the required input:
+```julia
+
+# Step 1: Define wing parameters
+n_panels = 20          # Number of panels
+span = 20.0            # Wing span [m]
+chord = 1.0            # Chord length [m]
+Umag = 20.0            # Magnitude of inflow velocity [m/s]
+density = 1.225        # Air density [kg/m³]
+alpha_deg = 30.0       # Angle of attack [degrees]
+alpha = deg2rad(alpha_deg)
+
+# Step 2: Create wing geometry with linear panel distribution
+wing = Wing(n_panels, spanwise_panel_distribution="linear")
+
+# Add wing sections - defining only tip sections with inviscid airfoil model
+add_section!(wing, 
+    [0.0, span/2, 0.0],    # Left tip LE 
+    [chord, span/2, 0.0],  # Left tip TE
+    "inviscid")
+add_section!(wing, 
+    [0.0, -span/2, 0.0],   # Right tip LE
+    [chord, -span/2, 0.0], # Right tip TE
+    "inviscid")
+
+# Step 3: Initialize aerodynamics
+wa = WingAerodynamics([wing])
+
+# Set inflow conditions
+vel_app = [cos(alpha), 0.0, sin(alpha)] .* Umag
+set_va!(wa, (vel_app, 0.0))  # Second parameter is yaw rate
+```
 
 Surfplan output file can be converted to an input for the vortex step method with a tool that is in this repo.
 
 ## Output
-- cl, cd, cs (side force coefficient)
-- spanwise distribution of forces
-  -> moment coefficients (not yet implemented)
+- CL, CD, CS (side force coefficient)
+- the spanwise distribution of forces  
+  --> moment coefficients (not yet implemented)
 
 ## Citation
 If you use this project in your research, please consider citing it.