Particle Image Velocimetry (PIV) is one of the techniques used to experimentally clarify fluid flow phenomena. The advantage of PIV is the ability to non-intrusively measure the instantaneous velocity vectors of a flow field at multiple points. The flow field around an actual vehicle has large-scale flow structures, and requires a wide measurement area. A large-scale PIV measurement technique was developed that can measure this type of large-scale flow field.An index capable of quantitatively evaluating the quality of the measurement was introduced, and the relationship between this index and the measurement accuracy was clarified. In addition, a seeding device that enables temporally and spatially uniform seeding of particles to the flow field, and a method to decrease laser light reflection were developed. Application of these technologies realized PIV measurement capable of evaluating an instantaneous velocity field over the large scale of 1.7 m x 1 m. A scanning system and integrated measurement software were also constructed, enabling multi-section measurement in a short time.
Article of Honda R&D Technical Review Vol.22 No.2 (109 - 117)