How to place a particle at the top of a Part?

I want to create a particle effect or part at the top of Part, but I can't make it work. Here's my script:

        local Plr = player
        local GroundWave = game:GetService("ReplicatedStorage").Spawncuccok.TesztPARTC

        local char = Plr.Character
        local mouse = Plr:GetMouse()
        local Humrp = char:WaitForChild("HumanoidRootPart")

        task.spawn(function()
            for i = 1,3 do
                local wave = GroundWave:Clone()
                wave.Parent = Humrp 

                wave.CFrame = Humrp.CFrame * CFrame.new(0,-2,0)

                game:GetService("TweenService"):Create(wave , TweenInfo.new(1),{Size = Vector3.new(175, 2.3, 172)}):Play()
                wait(0.3)
                game:GetService("TweenService"):Create(wave , TweenInfo.new(1),{Transparency = 1}):Play()
            --  print("part spawnolva!") debug
            end
        end)
        for i, v in pairs(char:GetDescendants()) do
            task.wait(5.5)
            if v:IsA ("TesztPARTC") then
                v:Destroy()
             end
            end