Honeycomb structure

A honeycomb structure comprising:

• a pillar-shaped honeycomb structure body which has porous partition walls disposed to surround a plurality of cells that provide fluid through channels extending from a first end face to a second end face;
• and a circumferential wall disposed to surround the partition walls,
• wherein, among the partition walls surrounding one of the cells, each of two of the partition walls constituting two opposite sides of the cell sandwiched therebetween is provided with a projection which projects to extend into the cell and which is continuously provided in a direction in which the cell extends,
• only two projections are included in each cell that is provided with projections,
• the two projections which project into the cell are disposed at positions where the interior of the cell is divided into two by a virtual line that virtually connects distal ends of the two projections in a section of the honeycomb structure body, the section being orthogonal to the direction in which the cell extends,
• in a case where the area of one region of the cell divided by the virtual line is denoted by S1, the area of the other region of the cell is denoted by S2, and S1≤S2, Equation (1) given below is satisfied:
• 70%≤S1/S2×100%, Equation (1):
• wherein a height H1 of each of the projections and a cell pitch H2 of the honeycomb structure body satisfy the relationship of Equation (2) given below:
• 15%≤H1/H2×100%≤40%;
• Equation (2):
• wherein a width W1 of each of the projections is 0.0127 to 0.203 mm;
• and
• wherein a cell density of the honeycomb structure is 31 to 155 cells/cm2.