Engine Database Selection Dialog

The Engine Database Selection Dialog in SpaceCAD 7 allows users to select rocket engines from a pre-configured database, providing crucial details about engine performance, including thrust curves, burn time, and impulse. This dialog is designed to help users select the most appropriate engine for their rocket, ensuring the engine fits within the design constraints and provides the necessary power for a successful flight.

Key Fields and Features:

1. Search for Engine (Search Bar)

• Allows users to search for a specific engine by name or code.
• This is useful when users know the exact motor they are looking for.

2. Filtered by Base Diameter (Automatic Filter)

• SpaceCAD automatically filters engines by diameter to ensure compatibility with the body tube or engine mount.
• Example: If the user is looking for a motor that fits an 18 mm motor mount, only motors with a base diameter of 18 mm will be shown.
• Users can click Clear Filter to display all motors, but must manually ensure that the selected motor fits the rocket design.

3. Manufacturer Filter (Left Panel)

• Filters the engine database by manufacturer.
• Popular manufacturers include:
  • Aerotech
  • Estes
  • FSI
  • Klima
  • Apogee
• Users can select one or multiple manufacturers to narrow the engine choices.

4. Engine List (Center Panel)

• Displays a list of available rocket engines with key specifications, including:
  • Motor (Delays): The engine model and available delay times (e.g., Estes A8 (3-5)).
  • Base Diameter: The diameter of the engine base, ensuring it fits in the motor mount (e.g., 18 mm).
  • Length: The total length of the motor.
  • Mass: The overall weight of the engine, which affects the rocket’s total weight and performance.
• Motor Delays: Indicated in brackets, providing the available ejection delay options (e.g., “3-5-7” means the engine can eject at 3, 5, or 7 seconds after burnout).

5. Engine Thrust Curve (Right Panel)

• Provides a graphical representation of the engine’s thrust over time.
• This curve allows users to see how the engine delivers power during the flight:
  • The x-axis represents time in seconds.
  • The y-axis represents thrust in Newtons (N).
• Example: The thrust curve for the Estes A8 shows a peak thrust of approximately 8 N at around 0.2 seconds, followed by a decrease in thrust.

6. Engine Specifications (Right Panel)

• Burntime: Total burn duration of the engine (e.g., 0.73 s for an Estes A8).
• Impulse: Total impulse provided by the engine, measured in Newton-seconds (Ns).
• Average Thrust: The engine’s average thrust over the burn duration (e.g., 3.19 N for an Estes A8).
• Propellant Weight: The weight of the propellant in grams, critical for performance and overall rocket weight.

7. Select Button

• After choosing an engine, users click Select to apply it to the rocket design.
• The engine is added to the rocket, and its properties, including mass, thrust, and impulse, are incorporated into the flight simulation.

8. Cancel Button

• Closes the dialog without selecting an engine.

Example Workflow:

1. Selecting an Engine for a Light Rocket:

   • Open the Engine Database Selection Dialog from the engine configuration section.
   • Ensure that the Filtered to Max Diameter option is enabled so that only engines that fit the rocket’s motor mount are displayed.
   • Choose a small, low-power engine like the Estes A8, which has a short burn time and relatively low average thrust.
   • Review the thrust curve to ensure the engine provides sufficient power for liftoff and click Select.

2. Choosing an Engine for High Altitude:

   • Open the Engine Database Selection Dialog.
   • Remove the automatic diameter filter by clicking Clear Filter.
   • Use the Manufacturer Filter to select high-power engines from Aerotech.
   • Choose a motor with high impulse and long burn time to achieve higher altitudes.
   • Analyze the thrust curve to see how the engine performs over time before clicking Select.

Important Notes:

• Automatic Filtering: When users cannot find an engine, it is often because the automatic filter is limiting engines based on diameter. Clicking Clear Filter will show all engines, but the user must ensure that the selected engine fits the rocket.
• Thrust Curves: The thrust curve graph is critical for understanding how the engine will perform during flight. The peak thrust value indicates the initial power at liftoff, and the curve’s shape shows how long the thrust will sustain.

Diagram Explanation:

A flowchart could illustrate the process of selecting an engine, factoring in thrust, burn time, and fitting requirements. Additionally, a visual explanation of the thrust curve would help users understand how it affects flight performance.

This documentation ensures users can effectively select the appropriate rocket engine from the database and understand the significance of key engine parameters in the Engine Database Selection Dialog of SpaceCAD 7.