🔗 Engineering Calculator Relationships
Data Flow, Dependencies & Workflow Integration
📊 Tools by Category
⚙️ Rotational & Power
Torque·Power·Speed
Electrical Power
Pump Head·Pressure
💨 Flow Networks
Continuity Equation
Pressure Drop
Reynolds Number
🔥 Thermal Analysis
Heat Transfer Rate
🔩 Structural
Stress from Pressure
🔄 Cross-Discipline
Universal Converter
🔄 Universal Hub
🔄 UNIVERSAL CONVERTER (200+ Unit Pairs)
⬇️ ⬆️
All 9 specialist tools reference this converter for flexible unit input/output.
Categories: Length, Area, Volume, Mass, Force, Pressure, Power, Temperature
Categories: Length, Area, Volume, Mass, Force, Pressure, Power, Temperature
⚙️ Power System Integration
Motor Spec
(V, I, PF)
(V, I, PF)
→
Electrical Power
P = √3·V·I·cos(φ)
P = √3·V·I·cos(φ)
→
Mechanical
Power (kW)
Power (kW)
→
Torque·Power·Speed
P = T × ω
P = T × ω
Workflow: Electrical load (kW) → Mechanical requirement → Verify against motor nameplate →
Calculate shaft duty for pump, fan, or compressor
💨 Pipe System Design Chain
Spec:
Flow (GPM)
Flow (GPM)
→
Continuity Equation
Q = V × A
Q = V × A
→
Pipe D,
Velocity (m/s)
Velocity (m/s)
↓
Velocity,
Diameter
Diameter
→
Reynolds Number
Re = ρVD / μ
Re = ρVD / μ
→
Flow Regime
Friction Factor
Friction Factor
↓
f, L, D,
V, ρ
V, ρ
→
Pressure Drop
ΔP = f(L/D)(ρV²/2)
ΔP = f(L/D)(ρV²/2)
→
System
Head Loss
Head Loss
↓
Head
(m)
(m)
→
Pump Head·Pressure
P = ρgH
P = ρgH
→
Pump
Selection (bar)
Selection (bar)
Workflow: Volume flow → Pipe size & velocity check → Friction factor from Reynolds →
Total system head loss → Convert to pressure for pump spec
🔥 Thermal Duty Calculation
Process:
T_in, T_out, ṁ
T_in, T_out, ṁ
→
Heat Transfer Rate
Q = ṁ·Cp·ΔT
Q = ṁ·Cp·ΔT
→
Cooling Load
(kW)
(kW)
Workflow: Specify mass flow, inlet/outlet temps → Calculate duty → Size cooler or condenser →
Verify flow rate with Continuity Equation
🔩 Pressure Vessel Design
Design
Pressure (bar)
Pressure (bar)
→
Stress from Pressure
σ = P·r / t
σ = P·r / t
→
Hoop & Long.
Stress (MPa)
Stress (MPa)
Workflow: Design pressure from system duty → Calculate stresses → Select wall thickness to
keep stress below material yield → Verify against ASME code
📋 Common Workflows
Workflow 1: Pump Selection
1
Given: Volumetric flow (GPM) → use Continuity Equation
2
Calculate: Pipe velocity → use Reynolds Number for regime
3
Calculate: Friction factor → use Pressure Drop
4
Convert: Head loss → use Pump Head·Pressure
5
Calculate: Pump power → use Torque·Power·Speed OR Electrical Power
6
Check: Design pressure → use Stress from Pressure for vessel
Workflow 2: Motor Duty Verification
1
Mechanical spec: Torque (N·m), Speed (rpm) → use Torque·Power·Speed
2
Result: Required power (kW) with load
3
Motor selection: Voltage, current, PF → use Electrical Power
4
Verify: Electrical input ≥ Mechanical requirement (accounting for efficiency)
5
Cross-check: Use Universal Converter for power units (hp ↔ kW)
Workflow 3: Heat Exchanger Design
1
Process conditions: Flow, inlet/outlet T → use Heat Transfer Rate
2
Result: Cooling/heating duty (kW)
3
Shell-side flow check → use Continuity Equation for velocity
4
4
Tube-side flow check → use Continuity Equation for velocity
5
Pressure drop verification → use Pressure Drop for both sides
Workflow 4: Vessel Thickness Design
1
System pressure spec (bar) → use Stress from Pressure
2
Material yield stress (MPa) → select wall thickness to limit stress
3
Check: Thin-wall criterion (t/r < 0.1) or use thick-wall formulas
4
Verify: Apply code safety factor (ASME Section VIII)
5
Use Universal Converter for mixed unit specs
📋 Input/Output Data Dependencies
| Tool | Primary Inputs | Primary Outputs | Commonly Feeds Into |
|---|---|---|---|
| Continuity Equation | Flow (Q), Velocity (V), Area (A) | Any two unknowns solved | Pressure Drop, Reynolds #, Heat Transfer |
| Reynolds Number | ρ, V, D, μ | Re value, flow regime, friction factor range | Pressure Drop (for f selection) |
| Pressure Drop | f, L, D, V, ρ | ΔP | Pump Head·Pressure (converts to head), System design |
| Pump Head·Pressure | P, ρ (or H, ρ) | H (or P) | Torque·Power·Speed (pump power), Motor sizing |
| Torque·Power·Speed | Any two of: P, T, N | Third variable (and intermediate results) | Electrical Power (for motor verification) |
| Electrical Power | V, I, cos(φ) | P (kW), Q, S | Torque·Power·Speed (mechanical equivalent) |
| Heat Transfer | ṁ, Cp, ΔT (or U, A, LMTD) | Q (kW) | Continuity Equation (for cooler sizing) |
| Stress from Pressure | P, r, t, vessel type | σ_hoop, σ_long, τ_max | Code compliance checks, material selection |
| Universal Converter | Any value in supported units | Same value in any converted unit | All tools (for flexible unit input/output) |
📐 Key Formulas at a Glance
Power Relationships
P = T × ωP(kW) = T(N·m) × N(rpm) / 9549.3
P = V × I × cos(φ)
Flow & Continuity
Q = V × ARe = (ρ × V × D) / μ
ΔP = f × (L/D) × (ρV²/2)
Head & Pressure
P = ρ × g × HH = P / (ρ × g)
P_pump = Q × ρ × g × H / 1000
Thermal Energy
Q = ṁ × Cp × ΔTQ = U × A × LMTD
P_loss = I²R
Vessel Stresses (Thin-Walled)
σ_hoop = P × r / tσ_long = P × r / (2t)
τ_max = P × r / (4t)
Three-Phase Power
P = √3 × V × I × cos(φ)Q = √3 × V × I × sin(φ)
S = √3 × V × I