New signing Joey Pelupessy was named as a substitute after arriving in midweek for a reported fee of £500,000.
But there was a debut for young defender Jordan Thorniley.
Cardiff had the majority of the possession in the first half, and the Owls were thankful to goalkeeper Joe Wildsmith for keeping out Kenneth Zohore and Marco Grujic.
But the Owls improved as the game went on, and Jordan Rhodes had two good chances to open the scoring.
First, he headed over from six yards out, then he was played through but with only Neil Etheridge to beat, the visiting keeper parried the ball away and Adam Reach fired the loose ball into the stand.
Rhodes turned provider in the second half, floating in a teasing cross but Joao failed to get the power on his header and it was an easy save for Etheridge.
But despite several promising openings, the Owls lacked the cutting edge in front of goal to break down the City rearguard.
It was a third consecutive clean sheet for the Owls under Luhukay.
Wednesday manager Luhukay said: “It was a very hard game. Cardiff had a good team with strong, physical players. They were also dangerous.
“I think in the first half we had problems controlling the game but we did not give a lot of chances away.
“Cardiff in the first half had two or three chances but at the end of the first half we had two good chances to score.
“In the second half, we had two or three very good chances to score.
“The defending over 90 minutes was stable. We have good work in the defending.
“I’ve seen my team in a third game and I can live with my team. We are working intensively every day and we have made steps.”