Design and Testing of an ISO 5801 Inlet Chamber Test Rig and Related Issues with the Standard

Test Rig & Instrumentation

A rig has been designed and constructed according to the ISO 5801 standard, to test fans with a maximum inlet diameter equal to 0.8 m. The rig features an inlet chamber configuration and a multi-nozzle system for the flow-rate measurements. Before starting the design process a deep study of the ISO Standard has been carried out and two issues emerged: i) even if the requirements of all the components and rig parts are identified, a direct design procedure is not available in the Standard or in the literature; ii) some incoherent informations exist within the Standard. This last aspect is particularly tedious for the rig designer, because these ambiguities translate into a deeper analysis of the flow phenomena and a consequent interpretation of the Standard. These issues increase the time required for the design process and, in turn, the costs. Regarding the positioning of the nozzles on the wall between the two chambers for instance, the Standard does not clarify if a symmetrical allocation (with respect to the chamber longitudinal axis) is mandatory or recommended. Another unclear aspect deals with the operational differences among inlet chambers of type 1, 2, and 3.
In this work the design and construction of the ISO 5801 test rig installed at the University of Padova, Italy is described. The rig has been designed for a maxium flow-rate of ~ 8 m3/s and for a maximum negative pressure of 10000 Pa (~0.1 atm). The rig design has been organized into a direct procedure that can be easily applied by anyone interested in designing a rig with this common configuration. Furthermore, all the issues related to the Standard and encountered during the design process are highlighted and discussed.
The commissioning of the rig is presented as well; leakage tests were performed with the two-phase technique suggested by the Standard. Moreover, a case-study 800 mm Vane-Axial fan has been tested with different fan and rig configurations; the data collected are presented and discussed.
The aim of the paper is twofold: i) providing to anyone who is interested in designing an inlet chamber test rig with a direct procedure to perform satisfactorily the design of the facility, and ii) focusing the attention on some issues contained within the ISO 5801 Standard and suggesting possibile corrections/improvements.