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Full Vehicle NVH
Access the Assemble, Analyze, NVH Tools, NVH Post, and Physics AI ribbons.
Post-Processing and Diagnostics
Define radiation conditions and create emissivity models.
Flow Induced Noise/General Signal Processing
The General Signal Processing utility processes the time domain pressure results from CFD simulations and visualizes the results in both the time and frequency domain.
General Signal Processing - Probes Tab
The Probes tab is active for all input file types.

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What's New
View new features for HyperMesh NVH 2024.1.
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Learn the basics and discover the workspace.
Tutorials
Discover NVH functionality with interactive tutorials.
Full Vehicle NVH
Access the Assemble, Analyze, NVH Tools, NVH Post, and Physics AI ribbons.
- Assembly
  Learn how to create, open, import and save models.
- Analysis
  Set up the simulation model, materials, domains and boundaries.
- NVH Tools
- Prepare Module
  Create, organize and manage the CAE parts.
- Post-Processing and Diagnostics
  Define radiation conditions and create emissivity models.
  - Load an NVH Utility
  - Integrated Diagnostics
    Calculate a response, perform contribution analysis, plot results, and perform diagnostic studies and study response changes.
  - Modal Participation
    Plot modal/panel participation curves from an OptiStruct .h3d file or an MSC Nastran .f06/.pch file.
  - Grid Participation
    The Grid Participation utility allows you to plot panel grid participation results and then use advanced scaling contour capabilities to isolate key contributing areas.
  - Energy Distribution
    Visualize the distribution of energy within a full vehicle NVH model, as a way to understand what components are dominating the vehicle response.
  - Transfer Path Analysis
    Identifies the complex contribution of the excited structure through attachment points to a response in the responding structure.
  - Design Sensitivity Analysis
    Design sensitivity represents a change in response with respect to a change in a design variable, which is typically used for optimization.
  - Order Analysis
    Generates and post-processes engine order related data from an OptiStruct or Nastran frequency response analysis that contains either RPM-based loading subcases or order-based loading subcases.
  - Modal FRF
    Calculate a frequency response based on modal results.
  - Model Correlation
    The Model Correlation utility determines the degree of similarity or correlation between two sets of results.
  - Radiated Sound
    The Equivalent Radiated Sound utility post-processes the results of exterior structure-borne radiated sound.
  - Global Modes
    Identifies global modes from an OptiStruct or Nastran modal analysis.
  - Flow Induced Noise/General Signal Processing
    The General Signal Processing utility processes the time domain pressure results from CFD simulations and visualizes the results in both the time and frequency domain.
    - General Signal Processing - Load Tab
      Loads the ultraFluidX transient results file. Input file formats *.csv, *.h3d, and *.case are supported.
    - General Signal Processing - Probes Tab
      The Probes tab is active for all input file types.
    - General Signal Processing - Surface Tab
      The Surface tab is active when an H3D file or CASE file containing time domain flow pressure results are loaded into the utility.
  - Green House Noise
    Post-process the pressure result of a vehicle panel obtained from ultraFluidX.
  - Mount Optimization
    Predicts powertrain rigid body mode frequencies and kinetic energy distribution, which play a critical role in optimizing the mount stiffness and layout configuration, by decoupling powertrain rigid body modes and reducing vibration transmission.
  - Optimization, RBDO
    Optimizes sensitive parameters for multiple sample analysis results using the RBDO or Deterministic approach.
  - Multiple Sample Analysis
    Post-process results from a Multiple Sample Analysis, including plotting a spread of responses (+/-95% and mean).
  - Deterministic Optimization
    Reads results from an OptiStruct optimization run and processes the results to review the overlay of the NVH responses, baseline versus optimized. Compare changes in the design variable values, baseline versus optimized.
  - Display Options
    Customize plots using the following options
  - Filter Contributors
    Filters contributors to a smaller set of data.
High Frequency NVH
High frequency NVH is an implementation of Statistical Energy Analysis (SEA), and is used to predict and analyze the vibration and acoustic response of complex dynamic systems.
Squeak and Rattle
Create and evaluate evaluation lines and optimize interfaces to eliminate squeak and rattle issues.

View All Altair HyperWorks Help

General Signal Processing - Probes Tab

The Probes tab is active for all input file types.

Figure 1. General Signal Processing utility - Probes tab

Element selections

Select the single element or multiple elements corresponding to the results to display.

Select single elements by:

Element ID
Co-ordinates
Selection

The closest element within a 5mm radius is selected for the Co-ordinates option.

Select Satellite Probe if multiple elements are selected within a specified radius with center as the previously selected single element choice.

For the *.csv input file type, only element selection by element ID is supported.

The All Probes option processes and displays results for all probes contained in file.

Input Signal Selection

In this section, specify the input file time domain data and modify the time data to be used for processing.

The Input Time Duration, along with the total number of time steps and sampling frequency, is displayed.

The Time Duration of the transient domain signal is provided, and the number of time steps corresponding to the time duration is displayed.

Reset resets the time duration to the input time duration obtained from the file.

Click Advanced Options to chose the Cp-to-pressure conversion factor, which needs to be multiplied by the input time domain signal.

Figure 2. General Signal Processing Utility - Frequency Spectrum

Figure 3. General Signal Processing Utility - Time Domain Signal

Output Request

Specify the output request parameters.

Specify the response type: transient or frequency domain.

If the response type = frequency domain, specify Scale, Output Type (PSD or SPL), Plot Type, and Frequency Range.

Scale options include dB or dBA.

Output Type options include narrowband or broadband.

Broadband types, such as Octave, 1/3 Octave, 1/8 Octave, and 1/12 Octave, are supported for the SPL output type.

The upper limit of the frequency range can be up to half of the sampling frequency, and the lower limit can be reciprocal - four times the time duration.

Signal Processing Parameters

If the output response type is Frequency Domain, then specify signal processing parameters. Options include:

Block Size
Bandwidth
Overlap %
Time Windowing options, such as Hanning, Hamming, and Blackman.

Select Display Options and Display to edit and display results.

Use Export Data to output results to a CSV file.