Math & Numbers
Compute the drag force on a body in a fluid stream: F_D = ½·ρ·v²·C_D·A (N), where ρ is the fluid density, v the free-stream velocity, C_D the drag coefficient (shape- and Reynolds-dependent), and A the reference (frontal projected) area. A built-in shape library supplies typical high-Re C_D values: sphere 0.47, hemisphere 0.42, long cylinder 0.81, disk/flat plate 1.17, cube 1.05, streamlined airfoil 0.04, long streamlined ellipsoid 0.07, cone 0.50; or choose 'Custom' to enter C_D directly. Optionally, with dynamic viscosity μ and characteristic length L, the Reynolds number Re = ρ·v·L/μ is computed, and the power dissipated by drag P = F_D·v (W). Density in kg/m³/g/cm³, velocity in m/s/km/h, area in m²/cm²/mm², length in m/cm/mm.
Call this tool from your code in three languages.
curl -X POST 'https://api.elysiatools.com/en/api/tools/drag-force-calculator' \
-H 'Content-Type: application/json' \
-d '{"shapeType":"sphere","dragCoeff":0.47,"density":1.225,"densityUnit":"kg/m3","velocity":20,"velocityUnit":"m/s","referenceArea":1,"areaUnit":"m2","dynamicViscosity":0,"charLength":0,"lengthUnit":"m","decimalPlaces":4}'Send a POST request with your inputs as JSON. File parameters require a separate upload first.
POST https://api.elysiatools.com/en/api/tools/drag-force-calculator| Name | Type | Required | Description |
|---|---|---|---|
| shapeType | select | No | Body shape. Selecting a preset fills the typical drag coefficient C_D for that shape at high Reynolds number. Choose 'Custom' to enter C_D directly. |
| dragCoeff | number | Yes | Drag coefficient C_D (0 to 5). When a preset Shape is selected, the typical value is filled in automatically; you may still override it. Choose Shape = Custom to enter your own value. |
| density | number | Yes | Fluid density ρ. Enter in the selected Density Unit. |
| densityUnit | select | No | — |
| velocity | number | Yes | Free-stream velocity v. Enter in the selected Velocity Unit. |
| velocityUnit | select | No | — |
| referenceArea | number | Yes | Reference (frontal projected) area A. Enter in the selected Area Unit. |
| areaUnit | select | No | — |
| dynamicViscosity | number | No | Dynamic viscosity μ of the fluid in Pa·s. Optional — when supplied together with a characteristic length L, the Reynolds number Re = ρ·v·L/μ is computed. |
| charLength | number | No | Characteristic length L of the body. Optional — used only to compute Re. Enter in the selected Length Unit. |
| lengthUnit | select | No | — |
| decimalPlaces | number | No | — |
JSON result
{
"key": {...},
"metadata": {
"key": "value"
},
"error": "Error message (optional)",
"message": "Notification message (optional)"
}Add this tool to your Model Context Protocol server so AI agents can list and call it.
Add this block to your MCP client configuration:
{
"mcpServers": {
"elysiatools-drag-force-calculator": {
"name": "drag-force-calculator",
"description": "Compute the drag force on a body in a fluid stream: F_D = ½·ρ·v²·C_D·A (N), where ρ is the fluid density, v the free-stream velocity, C_D the drag coefficient (shape- and Reynolds-dependent), and A the reference (frontal projected) area. A built-in shape library supplies typical high-Re C_D values: sphere 0.47, hemisphere 0.42, long cylinder 0.81, disk/flat plate 1.17, cube 1.05, streamlined airfoil 0.04, long streamlined ellipsoid 0.07, cone 0.50; or choose 'Custom' to enter C_D directly. Optionally, with dynamic viscosity μ and characteristic length L, the Reynolds number Re = ρ·v·L/μ is computed, and the power dissipated by drag P = F_D·v (W). Density in kg/m³/g/cm³, velocity in m/s/km/h, area in m²/cm²/mm², length in m/cm/mm.",
"baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=drag-force-calculator",
"command": "",
"args": [],
"env": {},
"isActive": true,
"type": "sse"
}
}
}After connecting to the SSE endpoint, list the exposed tools:
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/list"
}Invoke the tool by its id, passing arguments built from its parameters:
{
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"name": "drag-force-calculator",
"arguments": {
"shapeType": "sphere",
"dragCoeff": 0.47,
"density": 1.225,
"densityUnit": "kg/m3",
"velocity": 20,
"velocityUnit": "m/s",
"referenceArea": 1,
"areaUnit": "m2",
"dynamicViscosity": 0,
"charLength": 0,
"lengthUnit": "m",
"decimalPlaces": 4
}
}
}Questions or issues? Contact [email protected]