An aerosol-generating system comprising: a cartridge comprising a cartridge aerosol-forming substrate, the cartridge having an annular shape; and an aerosol-generating device having a first end, a second end and a length extending between the first end and the second end, the aerosol-generating device comprising: a liquid storage section comprising a liquid aerosol-forming substrate positioned within the liquid storage section; a first electric heater configured to heat liquid aerosol-forming substrate from the liquid storage section during use of the aerosol-generating system; a power supply section comprising a power supply and a controller for controlling a supply of electrical power from the power supply to the first electric heater; a device air inlet positioned between the first end and the second end of the aerosol-generating device; and a device air outlet positioned at the second end of the aerosol-generating device; wherein the power supply section has a first end forming the first end of the aerosol-generating device and a second end, wherein the liquid storage section has a first end configured for removable attachment to the second end of the power supply section and a second end forming the second end of the aerosol-generating device; wherein an outer surface of the aerosol-generating device forms a flange, wherein one of the first end of the liquid storage section and the second end of the power supply section forms the flange when the liquid storage section is attached to the power supply section; and wherein the aerosol-generating device is configured to receive the cartridge on the aerosol-generating device so that the cartridge is received against the flange when the cartridge is received on the aerosol-generating device, and wherein the device air inlet is positioned proximate the flange so that the cartridge at least partially overlies the device air inlet when the cartridge is received against the flange. a cartridge comprising a cartridge aerosol-forming substrate, the cartridge having an annular shape; and an aerosol-generating device having a first end, a second end and a length extending between the first end and the second end, the aerosol-generating device comprising: a liquid storage section comprising a liquid aerosol-forming substrate positioned within the liquid storage section; a first electric heater configured to heat liquid aerosol-forming substrate from the liquid storage section during use of the aerosol-generating system; a power supply section comprising a power supply and a controller for controlling a supply of electrical power from the power supply to the first electric heater; a device air inlet positioned between the first end and the second end of the aerosol-generating device; and a device air outlet positioned at the second end of the aerosol-generating device; a liquid storage section comprising a liquid aerosol-forming substrate positioned within the liquid storage section; a first electric heater configured to heat liquid aerosol-forming substrate from the liquid storage section during use of the aerosol-generating system; a power supply section comprising a power supply and a controller for controlling a supply of electrical power from the power supply to the first electric heater; a device air inlet positioned between the first end and the second end of the aerosol-generating device; and a device air outlet positioned at the second end of the aerosol-generating device; wherein the power supply section has a first end forming the first end of the aerosol-generating device and a second end, wherein the liquid storage section has a first end configured for removable attachment to the second end of the power supply section and a second end forming the second end of the aerosol-generating device; wherein an outer surface of the aerosol-generating device forms a flange, wherein one of the first end of the liquid storage section and the second end of the power supply section forms the flange when the liquid storage section is attached to the power supply section; and wherein the aerosol-generating device is configured to receive the cartridge on the aerosol-generating device so that the cartridge is received against the flange when the cartridge is received on the aerosol-generating device, and wherein the device air inlet is positioned proximate the flange so that the cartridge at least partially overlies the device air inlet when the cartridge is received against the flange.