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Intake Ramp Analysis

This module provides functions for analyzing multi-ramp external-compression intakes. Each ramp is treated as an oblique shock and the downstream Mach number and property ratios are computed sequentially.

Overview

A typical supersonic inlet uses one or more compression ramps to slow and compress the incoming flow. For an incoming Mach number $M_\infty$ and a list of ramp deflection angles $\theta_i$, the intake is modeled by applying the oblique-shock relations at each ramp. The function intake_ramp returns the Mach number after each shock along with density, pressure, and total-pressure ratios.

Functions

CompAir.intake_ramp — Function
intake_ramp(M_infty::Real, ramp_angle::Vector{<:Real}, gamma::Real=1.4)

Calculates the Mach number, density ratio, pressure ratio, total pressure ratio, and shock angle at each stage of a multi-stage ramp intake for given ramp angles, freestream Mach number, and specific heat ratio.

Arguments

  • M_infty::Real: Freestream (inlet) Mach number
  • ramp_angle::Vector{<:Real}: Ramp angles for each stage (degrees)
  • gamma::Real=1.4: Specific heat ratio

Returns

A NamedTuple containing:

  • M: Vector of Mach numbers at each stage (length n+1, where n is the number of ramps)
  • rho2_ratio: Vector of density ratios at each stage (length n)
  • p2_ratio: Vector of pressure ratios at each stage (length n)
  • p0_ratio: Vector of total pressure ratios at each stage (length n)
  • beta: Vector of shock angles at each stage (length n, degrees)
source

Function Details

intake_ramp

intake_ramp(M_infty, ramp_angle, gamma=1.4)

Compute the flow properties across a series of intake ramps.

Arguments:

  • M_infty::Real: Freestream Mach number
  • ramp_angle::Vector{<:Real}: Ramp deflection angles in degrees
  • gamma::Real=1.4: Specific heat ratio

Returns:

  • NamedTuple containing:
    • M: Vector of Mach numbers at each stage (length n+1)
    • rho2_ratio: Density ratios across each shock (length n)
    • p2_ratio: Pressure ratios across each shock (length n)
    • p0_ratio: Total-pressure ratios across each shock (length n)
    • beta: Shock angles in degrees (length n)

Algorithm:

  1. Initialize the Mach number array with M_infty.
  2. For each ramp angle, call solve_oblique to obtain the downstream Mach number and property ratios.
  3. Collect the results into vectors and return them as a NamedTuple.

Example:

julia> sol = intake_ramp(2.5, [10, 16])
(M = [2.5, 2.085, ...], rho2_ratio = [...], p2_ratio = [...], p0_ratio = [...], beta = [...])

See Also

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