Precharge · working pressures · gas volume
Hydraulic accumulator gas state
Inputs
User-entered absolute gas precharge pressure; no precharge guidance or selection is provided.
User-entered absolute maximum gas pressure state for the stated cycle; pressure rating is not assessed.
User-entered absolute minimum gas pressure state; it must exceed the stated precharge pressure for this bounded state relation.
User-entered gas volume at the declared precharge state; vessel geometry and usable volume are not selected.
User-entered exponent from 1 through 1.67; no isothermal/adiabatic/process selection is made.
Results
Literal gas volume at declared maximum pressure
4.5
Literal gas volume at declared minimum pressure
7.5
Literal usable fluid-volume difference
3
Declared polytropic exponent
1
—P₀·V₀ⁿ = P·Vⁿ; V(P) = V₀·(P₀/P)^(1/n); ΔVfluid = V(Pmin) − V(Pmax)
A first-pass number, not a code check, certification, or approval. Read the method and its limits below. What this is and is not.
Nearby: Hydrostatic pressure · Flow continuity · Pipe mean velocity · Bernoulli equation
Method
Formula, when it applies, and when it does not
Apply a polytropic exponent to absolute pressure and gas-volume states, then report gas volumes and usable fluid-volume difference without sizing an accumulator.
P₀·V₀ⁿ = P·Vⁿ; V(P) = V₀·(P₀/P)^(1/n); ΔVfluid = V(Pmin) − V(Pmax)
When
- Declared absolute pressures
- User-entered polytropic exponent
- Ideal polytropic gas-state relation
Don’t
- This applies a user-declared ideal polytropic gas-state relation to declared absolute pressures and precharge gas volume. It does not select an accumulator, precharge, gas, vessel technology, safety device, or operating pressure; infer temperature, derive a transient duty cycle, model flow/response, heat transfer, seal condition, capacity, safety, suitability, code compliance, or approval.