Design and optimize your pneumatic launcher with real physics calculations
| Type | Diameter | Mass | Cd |
|---|---|---|---|
| Golf Ball | 42.67 mm | 45.93 g | 0.24 |
| Tennis Ball | 66 mm | 57 g | 0.50 |
| Ping Pong | 40 mm | 2.7 g | 0.50 |
| Nerf Dart | 13 mm | 1.0 g | 0.40 |
| Valve Type | Size | Cv | Open Time |
|---|---|---|---|
| QEV | 1/4" | 0.80 | 3 ms |
| QEV | 3/8" | 1.50 | 3 ms |
| QEV | 1/2" | 3.40 | 3 ms |
| QEV | 3/4" | 6.50 | 4 ms |
| QEV | 1" | 10.00 | 5 ms |
| Sprinkler (Mod) | 3/4" | 2.00* | 30 ms |
| Sprinkler (Mod) | 1" | 3.50* | 25 ms |
| Sprinkler | 3/4" | 1.50* | 55 ms |
| Sprinkler | 1" | 2.80* | 50 ms |
* Sprinkler Cv values are effective values accounting for internal flow restrictions
Runs all variable sweeps for the selected goal and shows comparison charts
Flow rate comparison at different pressure differentials. QEVs provide significantly faster flow due to larger effective orifice and minimal internal restrictions.
Velocity increases roughly with square root of pressure. Current operating point shown in red.
| Nominal Size | OD (in) | ID (in) | Wall (in) | Pressure (psi) | Projectile Fit |
|---|
Exit Pressure:
Pexit = P0 × (V1/V2)γ
Adiabatic Work:
W = P0V1/(γ-1) × [1-(V1/V2)γ-1]
Muzzle Velocity:
v = √(2E / m)
Where:
γ = 1.4 (air)
V1 = chamber + dead space
V2 = V1 + barrel volume
Lift Force:
FL = ½ × CL × ρ × A × v²
Spin Factor:
S = ω × r / v
Where:
CL = lift coefficient ≈ 0.5 × S
ρ = air density (1.225 kg/m³)
A = cross-sectional area
ω = angular velocity (rad/s)
r = ball radius (m)
Transit Time:
ttransit = 2L / v (approx)
If ttransit ≥ topen:
ηv = 0.5×(topen/ttransit) + (1 - topen/ttransit)
If ttransit < topen:
ηv = ttransit / (2 × topen)
Cv Factor:
ηcv = min(1, √(Cv/5))
Drag Force:
FD = ½ × Cd × ρ × A × v²
Where:
Cd = drag coefficient
ρ = air density (1.225 kg/m³)
A = cross-sectional area (m²)
v = velocity (m/s)
Optimal angle: 30-40° with drag
Gap Ratio:
rgap = (Abar - Aproj) / Aproj
Flow Competition Model:
η varies by gap regime (0.02-0.40)
Tighter fits → higher efficiency
Threshold Pressure:
Pmin = 20 + (rgap × 80) psi
Below threshold: η² penalty
Where:
Abar = barrel cross-section
Aproj = projectile cross-section
P = operating pressure (psi)
η = ηbase × ηdyn (total)
Muzzle Energy:
E = W × (Aproj/Abar) × ηseal
Effective Energy:
Eeff = E × ηvalve × ηtype
Where:
W = adiabatic work (J)
ηseal = blow-by efficiency
ηvalve = valve open fraction
ηtype = 0.75 sprinkler, 1.0 QEV