# rrtheta

Compute relative temperature ratio

## Syntax

```th = rrtheta(t0, mach, g) ```

## Description

`th = rrtheta(t0, mach, g)` computes `m` temperature relative ratios, `th`, from `m` static temperatures, `t0`, `m` Mach numbers, `mach`, and `m` specific heat ratios, `g`. `t0` must be in kelvin.

## Examples

Determine the relative temperature ratio for three temperatures:

```th = rrtheta([273.15 310.9278 373.15], 0.5, 1.4) th = 0.9953 1.1330 1.3597```

Determine the relative temperature ratio for three temperatures and three different heat ratios:

```th = rrtheta([273.15 310.9278 373.15], 0.5, [1.4 1.35 1.4]) th = 0.9953 1.1263 1.3597```

Determine the relative temperature ratio for three temperatures at three different conditions:

```th = rrtheta([273.15 310.9278 373.15], [0.5 1 2], [1.4 1.35 1.4]) th = 0.9953 1.2679 2.3310```

## Assumptions and Limitations

For cases in which total temperature ratio is desired (Mach number is nonzero), the total temperature is 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 