Heated Three-Dimensional Turbulent Jets

Abstract

An experimental investigation of heated three-dimensional turbulent free jets is presented. Emphasis is placed on the basic character of such flows and their relation to their unheated counterparts and to heated axisymmetric jets. Temperature and velocity distributions indicate that these flow fields may be characterized by three distinct regions in terms of the axis decays: a potential core region where axis values are close to the exit values, a characteristic decay region wherein the axis decays are dependent upon orifice geometry, and an axisymmetric decay region where the axis decay is axisymmetric in nature and thus independent of orifice geometry. These regions are not exactly the same for temperature as for velocity, the former being shifted somewhat upstream of the latter. Half-width data indicate that heated three-dimensional jets change shape as they proceed downstream, ultimately becoming axisymmetric in nature, regardless of initial orifice shape. Profile characteristics and similarity are discussed as well as cross-plane contours of pertinent flow variables. Some of the effects of initial conditions and exit flow quality on the subsequent development of three-dimensional jets are shown and the sensitivity of such flows to these factors is described.