Salah's Model for Diesel Engine Intake Airflow
 | A major contributor to this article appears to have a close connection with its subject. (July 2025) |
An editor has nominated this article for deletion. You are welcome to participate in the deletion discussion, which will decide whether or not to retain it. |
Salah's model[1] is an analytical framework developed by Salah Elmoselhy[2] that provides a physically motivated, closed-form solution for estimating the intake air mass flow into diesel engine cylinders, accounting explicitly for the effects of a flexible crankshaft. The model addresses a key shortcoming in existing simulation frameworks like GT-Power and CMEM, which generally assume rigid crankshafts.[3]
Background
[edit]Crankshaft flexibility, although often ignored in traditional engine models, introduces notable inertial and pressure variations that can affect intake dynamics, especially at high rotational speeds. Salah Elmoselhy proposed a refined intake airflow model that integrates these dynamic effects through first-principle derivations.
Salah’s Analytical Model
[edit]The model, also referred to as Salah’s model, is derived from Newtonian mechanics and thermodynamic considerations of the intake process. The in-cylinder pressure during the intake phase is computed as a sum of:
- Manifold pressure,
- Vacuum effect due to piston acceleration,
- Flow-induced losses,
- Inertial effects from crankshaft rotation.
This results in a compact expression for the overall cylinder pressure, and subsequently for the total intake air mass flow.
Validation
[edit]Salah’s model has been validated using real-world drive cycles and has demonstrated improved accuracy over GT-Power and CMEM. It achieved mean prediction errors of:
- ~7.5% for the ORNL standard freeway cycle,
- ~11% for the EPA freeway cycle.
Impact
[edit]Salah’s model enables accurate, fast, and transparent airflow predictions for diesel engines operating under flexible mechanical conditions. It opens up new avenues for emission reduction strategies and control-oriented modeling.
See also
[edit]Bibliography
[edit]- ^ Elmoselhy, Salah A. M.; Faris, Waleed F.; Rakha, Hesham A. (2022-08-22). "Validated Analytical Modeling of Eccentricity and Dynamic Displacement in Diesel Engines with Flexible Crankshaft". Energies. 15 (16): 6083. doi:10.3390/en15166083. ISSN 1996-1073.
- ^ "Center for Physics of the University of Coimbra". cfisuc.fis.uc.pt. Retrieved 2025-07-12.
- ^ "How the crankshaft works - All the details". How a Car Works. Retrieved 2025-07-12.