## Rotational Analysis with no Tachometer Data

The identification of cyclic events in rotational analysis is often key to identifying problems. It is good practice to use a suitable sensor for capturing rotational speed. However, this is…

titanium and steel gears and cogwheels

## Analysis of Dynamic Engine Vibration – Angular Vibration in High Performance Engines

The analysis of dynamic engine vibration and the accurate measurement of angular vibration is a non-trivial task, as a more in-depth analysis of boundary conditions reveals. Tools for engine vibration…

Vehicle AC

## Analysis of Airflow Instabilities in HVAC units

HVAC (Heat Ventilation Air Conditioning) units are devices used in various applications, such as cars, buildings, aircraft etc. They facilitate the transport and conditioning (heating, cooling, changing of humidity) of…

## The Effect of the Nyquist Theory on Rotational Order Analysis

Nyquist theory is generally understood, but this understanding usually relates to time sampling and the conversion to the frequency domain. Rotational order analysis and the effect of the Nyquist frequency…

## How Many Samples Per Revolution Are Required To Study A Particular Order

When working in the synchronous/angle domain, how many samples per revolution are required to study a particular order.

To study the nth order we need $2*n$ samples per revolution. (more…)

## Engine Model Being Put Through Its Paces

Our engine model demonstrator being put through its paces. Runups, rundowns and 'overclocking' https://www.youtube.com/watch?v=jG7aVK7aBp0

## What is Synchronous (Angular) Sampling?

The term synchronous data is usually applied to vibration or acoustic data that is captured from an item of rotating equipment at regularly spaced angle intervals as distinct from regularly spaced time intervals. The rotating part could be an engine, a gear wheel, a drive shaft, a turbine rotor, a propeller, a turbocharger or any other type of rotary mechanical device. Typically these items are subjected to out-of-balance forces that cause them to vibrate at frequencies that are multiples of the fundamental (once per revolution) rotation speed frequency. (more…)

## How To Analyze & Measure Torsional Vibration

Knowing how to measure torsional vibration is of key importance in the area of vehicle development and refinement. The main contributory source is the engine where periodically occurring combustion cycles cause variation in the crankshaft rotary vibration. This vibration is transmitted to and modified further by other components in the powertrain such as the gearbox and by other equipment driven off the drive belt or chain. Additional torsional vibrations are also likely to appear downstream at the drive shafts and wheels.

## Evaluating A Closed Loop Control System For High Pressure Pumps

Prosig were recently involved in the validation of a closed loop control system for an automotive pump supplier. The customer has a large number of test cells, each test cell has 8 pumps continually on test. Each pump is instrumented with a revolution or tachometer sensor, giving a once per revolution tachometer pulse. Additionally, there are various analogue transducers on each pump which measure parameters, such as pressure at the pump inlet and outlet.