Radiation Stress Flux SX

Compute monochromatic linear-wave shore-normal and cross radiation stresses with caller group/phase ratio and incident angle; no surf-zone closure is assumed.

Description

Radiation stress represents the wave contribution to mean momentum flux.

Radiation stress represents the wave contribution to mean momentum flux. Shore-normal and longshore components have different angle dependence.

Compute monochromatic linear-wave shore-normal and cross radiation stresses with caller group/phase ratio and incident angle; no surf-zone closure is assumed.

When to use Radiation Stress Flux SX

Use this tool to compute monochromatic linear-wave shore-normal and cross radiation stresses with caller group/phase ratio and incident angle; no surf-zone closure is assumed.

Gather the water, wave, current or profile observations and any supplied calibration constants. Confirm units and the stated coordinate and pressure conventions.

How to use Radiation Stress Flux SX and understand its results

Gather the water, wave, current or profile observations and any supplied calibration constants. Confirm units and the stated coordinate and pressure conventions.
Enter waveHeightM, waterDensityKgPerM3, gravityMPerSecondSquared, groupToPhaseSpeedRatio, angleFromShoreNormalDegrees using the field table and calculation rules, then run the tool.
Read waveEnergyJPerM2, shoreNormalRadiationStressNPerM, longshoreRadiationStressNPerM. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
waveHeightM	Wave height m	number	Required
waterDensityKgPerM3	Water density kg per m3	number	Required
gravityMPerSecondSquared	Gravity m per second squared	number	Required
groupToPhaseSpeedRatio	Group to phase speed ratio	number	Required
angleFromShoreNormalDegrees	Angle from shore normal degrees	number	Required

Use positive density/gravity, nonnegative height, group/phase ratio n in [0.5,1] and angle strictly in (−90,90). Return energy, Sxx and signed Sxy = energy × n × sin(angle)cos(angle).^[1]

energy = ρgH²/8; Sxx = energy[n(1 + cos²angle) − 0.5]

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
waveEnergyJPerM2	Wave energy j per m2	number
shoreNormalRadiationStressNPerM	Shore normal radiation stress n per m	number
longshoreRadiationStressNPerM	Longshore radiation stress n per m	number

json

{
  "input": {
    "waveHeightM": 2,
    "waterDensityKgPerM3": 1000,
    "gravityMPerSecondSquared": 10,
    "groupToPhaseSpeedRatio": 0.5,
    "angleFromShoreNormalDegrees": 0
  },
  "output": {
    "waveEnergyJPerM2": 5000,
    "shoreNormalRadiationStressNPerM": 2500,
    "longshoreRadiationStressNPerM": 0
  }
}

Limitations and assumptions

Linear monochromatic waves are assumed; no surf-zone closure is supplied.

Numbers and computed results must be finite; overflow produces an error. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Wave Setup Superelevation Surf Zone: Integrate steady wave-stress setup increments over supplied interval depths relative to the offshore start; neglects setup feedback on depth, currents and breaking closures. For a complementary task, use Littoral Drift Longshore Sediment Rate: Screen signed CERC-form bulk sediment transport with supplied breaker state/coefficient; no sediment supply, directional convention or validated shoreline evolution is inferred.

References

Radiation Stress Flux SX — tool.io

Similar or alternative tools

Wave Setup Superelevation Surf Zone
Integrate steady wave-stress setup increments over supplied interval depths relative to the offshore start; neglects setup feedback on depth, currents and breaking closures.
Littoral Drift Longshore Sediment Rate
Screen signed CERC-form bulk sediment transport with supplied breaker state/coefficient; no sediment supply, directional convention or validated shoreline evolution is inferred.