@article{alternatively:11074,
      recid = {11074},
      author = {Vollbrandt, J and Coraddu, A and Geertsma, R},
      title = {Transient performance of alternatively fueled internal  combustion engines for naval applications},
      journal = {Conference Proceedings of EAAW},
      address = {2023-11-28},
      abstract = {Navies worldwide are exploring the use of alternative  fuels for their vessels, aiming to cut down greenhouse gas  emissions and lessen their reliance on fossil fuels. This  effort also seeks to reduce their environmental impact and  emissions signatures. However, combustion engines running  on low reactivity fuels, including most
alternative fuels  like natural gas or alcohols, are limited by their lower  load acceptance compared to diesel engines. As a result,  they may not meet the stringent naval requirements for  dynamic load capacity in power generation. A high dynamic  loading capacity is a precondition for high maneuverability  of the vessel on the one hand and handling of pulsed power  loads and step loads caused by rail-guns and directed  energy weapons on the other hand. Previous research into  the dynamic response of natural gas engines required  detailed in-cylinder combustion models to predict knock.  These 0D/1D simulation models rely on extensive data to  calibrate the combustion model, which is generally  unavailable to the naval engineer designing a propulsion or  energy system. Additionally, these simulation models  require a significant amount of computational power and do  rarely run in real-time. This study predicts the dynamic  response using a Mean Value First Principle (MVFP) engine  model based on the filling and emptying approach and  turbocharger performance maps derived from limited data and  measurements.
Initially, the model is calibrated using  engine data provided by the manufacturer and experimental  measurements in steady state on a spark-ignited Caterpillar  3508A gas engine driving a generator at a constant speed of  1500 rpm. Additional calibrations are performed using  experimental measurements of the dynamic response to step  loads. Analysis of the simulation results reveals the  model’s capability to predict the dynamic response of the  air intake and exhaust system while being able to run in  real-time. The results further show that steady-state  simulations do not consider the effect of turbocharger  inertia and lagging fresh air supply on the thermal loading  and knock probability of the engine sufficiently. This  paper underlines the significance of implementing the air  and exhaust path dynamics,
including turbocharger  performance models, in mean-value models when investigating  combustion engines operating on low reactivity fuels.  Furthermore, the
paper provides guidance on the minimum  required number of measurements and load steps to calibrate  a mean value model for the prediction of the  engine
operating parameters under dynamic loads. The  resulting model can be used to establish limitations for  the loads on the electric grid and evaluate  control
strategies to improve the combustion engine  generator and electrical systems’ performance.},
      url = {http://library.imarest.org/record/11074},
      doi = {https://doi.org/10.24868/11074},
}