Volumetric intake flow measurements of an IC engine using magnetic resonance velocimetry

Abstract

Magnetic resonance velocimetry (MRV) measurements are performed in a 1:1 scale model of a singlecylinder optical engine to investigate the volumetric flow within the intake and cylinder geometry during flow induction. The model is a steady flow water analogue of the optical IC-engine with a fixed valve lift of 9:21 mm to simulate the induction flow at crank-angle 270 bTDC. This setup resembles a steady flow engine test bench configuration. MRV measurements are validated with phaseaveraged particle image velocimetry (PIV) measurements performed within the symmetry plane of the optical engine. Differences in experimental operating parameters between MRV and PIV measurements are well addressed. Comparison of MRV and PIV measurements is demonstrated using normalized mean velocity component profiles and showed excellent agreement in the upper portion of the cylinder chamber (i.e., y ! À 20 mm). MRV measurements are further used to analyze the ensemble average volumetric flow within the 3D engine domain. Measurements are used to describe the 3D overflow and underflow behavior as the annular flow enters the cylinder chamber. Flow features such as the annular jet-like flows extending into the cylinder, their influence on large-scale in-cylinder flow motion, as well as flow recirculation zones are identified in 3D space. Inlet flow velocities are analyzed around the entire valve curtain perimeter to quantify percent mass flow rate entering the cylinder. Recirculation zones associated with the underflow are shown to reduce local mass flow rates up to 50 %. Recirculation zones are further analyzed in 3D space within the intake manifold and cylinder chamber. It is suggested that such recirculation zones can have large implications on cylinder charge filling and variations of the in-cylinder flow pattern. MRV is revealed to be an important diagnostic tool used to understand the volumetric induction flow within engine geometries and is potentially suited to evaluate flow changes due to intake geometry modifications.

A Combined Numerical and Experimental Study of the 3D Tumble Structure and Piston Boundary Layer Development During the Intake Stroke of a Gasoline Engine

“…For conventional engines at these operating conditions, potential compressibility effects during the intake stroke are limited to very small valve lifts and are considered negligible. Freudenhammer et al [22,23] showed that the intake stroke of a water analogue and a real engine matches well in the case of similar Reynolds numbers, which also justifies the use of water for this specific investigation here. The specifications are summarized in Table 1.…”

“…11a) results in a focussed flow between the angles of about −60 • and 60 • . This distribution is characteristic for these types of intake ports (see also [22,23]). For global information, the radial momentum flux through the evaluation area is integrated along the height of the valve gap.…”

Spatially Resolved Experimental and Numerical Investigation of the Flow through the Intake Port of an Internal Combustion Engine

“…"High-speed" PIV allows time-resolved investigations of in-cylinder flow structures and their development within a single cycle, while tomographic PIV enables volumetric measurements [10]. The mean threedimensional flow in the intake port was fully quantified using Magnetic Resonance Velocimetry (MRV) by Freudenhammer et al [11].…”

Scale-resolving simulations in engine combustion process design based on a systematic approach for model development

“…Other datasets relevant for engine combustion include the laboratory flames, for example, from the TNF workshop or engine-related flow bench data to characterize the intake flow. 21,110 Simulations of these systems can be performed at varying resolutions. As mentioned above, for engine combustion process design, the whole range from URANS-VLES to full-scale LES should be considered.…”