GTL Resonance Software


Resonance Overview | call (931) 455-7330 for a free demo

RESONANCE calculates the acoustic frequencies and motions in chambers with the influence of transonic flow.
RESONANCE is a remarkably accurate diagnostics tool designed to help our customers design better products. Enclosed volumes such as combustion chambers tend to vibrate at their natural frequencies. RESONANCE calculates the normal acoustic modes, including mode shapes, complex frequencies, and phase relationships with the influence of mixed subsonic, transonic and supersonic flow. RESONANCE can calculate the resonant mode shapes and frequencies for cavities and chambers in hours. It is a powerfully predictive tool that provides direct diagnostic insight into why behavior occurs, leading the way for innovation. Through efficiency and accuracy RESONANCE saves our customers time and money in the development process.
Application Areas
Liquid Rocket Engine
Solid Rocket Motors
Hybrid Rocket Engines
Scramjet Combustion Sections
Jet Engine Combustion Sections
Jet Engine Combustor Augmentors & Ducts

Key Features

• Analyzes just the frequency domain unsteady acoustic motions instead of a time-accurate CFD solution, yielding solutions in minutes to hours instead of weeks to months.
• Paralleized: Divide the analysis over multiple processors and networked machines with automatic load balancing of multiple grids
• Scalable: Analyze 3D or high frequency 2D resonance with large grids using RAM from networked machines
• 2D Cartesian, 2D Axisymmetric or full 3D as needed
• Use multiple blocks of connected structured grids to identify the volume
• Pull in steady flow CFD using standard Plot3D and Tecplot formats
• Automatically determines connectivity between multiple blocks
• Automated load balancing of computational grids between processors
• Based on a perturbation of the Euler equations, incorporating the influence of the steady flow velocity and speed of sound on the acoustic modes to generate a quadratic eigenvalue problem
• Accounts for phasing of acoustic mode shapes due to steady flow convection
• Sonic exhaust accurately treated automatically using upwinding or accounted for with a normal sonic line
• Nozzle admittance not required
• Uses industry standard ARPACK algorithms to solve the eigenvalue problem
• Liquid Rocket Engines
• Solid Rocket Engines
• Jet Engines
• Scramjets
• Provides diagnostic insight into why problems occur
• Saves time and money in the development process
• Runs on Ubuntu Linux 12.04 64 bit PCs (MS Windows users can run Ubuntu within Oracle’s VirtualBox for free)
• Fully functional time limited demonstration licenses available


RESONANCE allows you to evaluate how resonator cavities modify the acoustic mode shape of the chamber. Small changes in geometry can result in large changes in the acoustic field.


RESONANCE accounts for the influence of the transonic steady flow in sonic nozzles on the acoustic mode shapes. This provides an accurate exhaust boundary condition without resorting to admittance functions.


RESONANCE uses structured grids to model complicated geometries. The computations may be subdivided between multiple processors and networked machines by assigning grids to specific processors.


RESONANCE is compatible with Intel/AMD x86-64 processor computers running the Ubuntu 12.04 64-bit Linux operating system, version 3.2, and should work on similar configurations. It requires the installation of the OpenMPI 1.6.5 libraries or newer (available at for parallel processing. Please contact GTL if you require use of the program on a different platform.

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