Documentation

# rrdelta

Compute relative pressure ratio

## Syntax

```d = rrdelta(p0, mach, g) ```

## Description

`d = rrdelta(p0, mach, g)` computes `m` pressure relative ratios, `d`, from `m` static pressures, `p0`, `m` Mach numbers, `mach`, and `m` specific heat ratios, `g`. `p0` must be in pascals.

## Examples

Determine the relative pressure ratio for three pressures:

```delta = rrdelta([101325 22632.0672 4328.1393], 0.5, 1.4) delta = 1.1862 0.2650 0.0507```

Determine the relative pressure ratio for three pressures and three different heat ratios:

```delta = rrdelta([101325 22632.0672 4328.1393], 0.5, [1.4 1.35 1.4]) delta = 1.1862 0.2635 0.0507```

Determine the relative pressure ratio for three pressures at three different conditions:

```delta = rrdelta([101325 22632.0672 4328.1393], [0.5 1 2], [1.4 1.35 1.4]) delta = 1.1862 0.4161 0.3342```

## Assumptions and Limitations

For cases in which total pressure ratio is desired (Mach number is nonzero), the total pressures are calculated assuming perfect gas (with constant molecular weight, constant pressure specific heat, and constant specific heat ratio) and dry air.

## References

Aeronautical Vestpocket Handbook, United Technologies Pratt & Whitney, August, 1986 