Imperial College London


Faculty of EngineeringDepartment of Mechanical Engineering

Chair in Thermofluids



+44 (0)20 7594 7032p.aleiferis




Ms Serena Dalrymple +44 (0)20 7594 7029




615City and Guilds BuildingSouth Kensington Campus






BibTex format

author = {Hamzehloo, A and Aleiferis, PG},
doi = {10.4271/2013-01-2524},
journal = {SAE Technical Paper Series},
title = {Computational Study of Hydrogen Direct Injection for Internal Combustion Engines},
url = {},
volume = {2013},
year = {2013}

RIS format (EndNote, RefMan)

AB - Hydrogen has been largely proposed as a possible fuel forinternal combustion engines. The main advantage of burninghydrogen is the absence of carbon-based tailpipe emissions.Hydrogen’s wide flammability also offers the advantage ofvery lean combustion and higher engine efficiency thanconventional carbon-based fuels. In order to avoid abnormalcombustion modes like pre-ignition and backfiring, as well asair displacement from hydrogen’s large injected volume percycle, direct injection of hydrogen after intake valve closure isthe preferred mixture preparation method for hydrogenengines. The current work focused on computational studies ofhydrogen injection and mixture formation for direct-injectionspark-ignition engines. Hydrogen conditions at the injector’snozzle exit are typically sonic. Initially the characteristics ofunder-expanded sonic hydrogen jets were investigated in aquiescent environment using both Reynolds-Averaged NavierStokes(RANS) and Large-Eddy Simulation (LES) techniques.Various injection conditions were studied, including areference case from the literature. Different nozzle geometrieswere investigated, including a straight nozzle with fixed crosssection and a stepped nozzle design. LES captured details ofthe expansion shocks better than RANS and demonstratedseveral aspects of hydrogen’s injection and mixing. Incylindersimulations were also performed with a side 6-holeinjector using 70 and 100 bar injection pressure. Injectiontiming was set to just after inlet valve closure with duration of6 μs and 8 μs, leading to global air-to-fuel equivalence ratios typically in the region of 0.2–0.4. The engine intake airpressure was set to 1.5 bar absolute to mimic boostedoperation. It was observed that hydrogen jet wall impingementwas always prominent. Comparison with non-fuelled engineconditions demonstrated the degree of momentum exchangebetween in-cylinder hydrogen injection and air motion. LEShighlighted details of hydroge
AU - Hamzehloo,A
AU - Aleiferis,PG
DO - 10.4271/2013-01-2524
PY - 2013///
SN - 0148-7191
TI - Computational Study of Hydrogen Direct Injection for Internal Combustion Engines
T2 - SAE Technical Paper Series
UR -
UR -
VL - 2013
ER -