Analysis of Transient Compressible Gas Jets Using High Speed Schlieren Imaging
Journal article, 2013

Transient compressible gas jets, as encountered in direct injection gas fuel engines, have been examined using schlieren visualization. Helium has been injected into air in a pressure chamber to create the jets examined. The structure of the jets is studied from the mean and coefficient of variation of the penetration length, jet width and jet angle. The quantities are calculated by digital image processing of schlieren images captured with a high-speed camera. Injection pressure and chamber pressure have been varied to determine whether they have an effect on the response variables. Design of experiments methods have been used to develop the scheme employed in performing the experiments. The mean normalized penetration length of the jets is found to scale with injection to chamber pressure ratio and is in agreement with a momentum conserving relation given in the literature. The dispersion of the penetration length has been found to be in agreement with a normal distribution. The Turner model for a jet has been found to be in agreement with the observed jets. The jet has been observed to transition to self-similarity within 20 nozzle diameters. The calculated penetration constant Γ has been observed to vary with the pressure ratio and is smaller than previously reported values. The jet angle approaches a constant value for all cases and has also been found to be in approximate agreement with a normal distribution.

Author

Lars Christian Riis Johansen

Chalmers, Applied Mechanics, Combustion and Propulsion Systems

Eugenio De Benito Sienes

Chalmers, Applied Mechanics, Combustion and Propulsion Systems

Petter Dahlander

Chalmers, Applied Mechanics, Combustion and Propulsion Systems

SAE Technical Papers

01487191 (eISSN)

Areas of Advance

Transport

Subject Categories

Energy Engineering

Fluid Mechanics and Acoustics

Computer Science

DOI

10.4271/2013-01-0871

More information

Latest update

10/6/2023